Free 220-1101 Core 1 Practice Exam – 2025 Updated

A. Have the user unplug the heater: This addresses a potential power issue. Since the technician has already verified the monitor is receiving power, this step is less relevant as the immediate next action for a "no signal" problem.

B. Replace the monitor: Replacing hardware is a premature and costly step. It should only be considered after all simpler potential causes, such as cable connections and software settings, have been thoroughly investigated and ruled out.

C. Open the display settings on the computer: While checking software configuration is a valid troubleshooting step, it should typically follow the verification of physical connections. A disconnected cable will cause a "no signal" issue regardless of the computer's display settings.

1. CompTIA A+ Core 1 (220-1101) Exam Objectives, Objective 5.4: "Given a scenario, troubleshoot video, projector, and display issues." This objective covers common problems like "No display," for which the standard procedure involves checking power, cable connections, and input sources before moving to software or hardware replacement. The methodology prioritizes checking physical layer issues first.

2. Dell Technologies Official Documentation, Knowledge Base Article 000125799: "How to Troubleshoot Display or Video Issues on a Dell Monitor." The troubleshooting steps provided are ordered as follows: "Step 2: Verify that the video cable is connected correctly... Ensure that the video cable (VGA, DVI, HDMI, or DisplayPort) is connected securely to both the monitor and the computer." This confirms that checking the data cable is a primary step after a power check.

3. HP Customer Support Documentation, Document ID: c01982410: "HP PCs and Monitors - Troubleshooting screen issues (Windows 10, 8, 7)." In the section "The screen is blank or there is no display," the recommended first steps after checking power are: "Reconnect the video cable" and "Press the video source button on the monitor." This reinforces checking the physical connection as a foundational troubleshooting step.

A. Shared resources: This refers to the multi-tenant model where multiple customers share the same physical infrastructure. It is a core concept for efficiency and cost-effectiveness, not reliability.

C. Rapid elasticity: This is the ability to quickly and automatically scale computing resources up or down as needed. It relates to performance and cost optimization, not system uptime or reliability.

D. Hybrid: This is a cloud deployment model that combines public and private clouds. While a hybrid architecture can be designed for high availability, the term itself does not inherently define reliability.

1. Amazon Web Services (AWS). (2023). AWS Well-Architected Framework: Reliability Pillar. "The Reliability pillar includes the ability of a workload to perform its intended function correctly and consistently when it’s expected to. This includes the ability to operate and test the workload through its total lifecycle. Foundational elements around networking and compute, such as high availability, are covered in this pillar." Retrieved from AWS Whitepapers & Guides. (Specifically, the introduction to the Reliability Pillar).

2. Microsoft Azure. (2023). Availability options for Azure Virtual Machines. "High availability is a term that denotes a system or component that is continuously operational for a desirably long length of time. Availability is usually expressed as a percentage of uptime in a given year." (Section: "What is high availability?").

3. Mell, P., & Grance, T. (2011). The NIST Definition of Cloud Computing (NIST Special Publication 800-145). National Institute of Standards and Technology. https://doi.org/10.6028/NIST.SP.800-145. (This document defines "Resource Pooling" (Shared Resources) and "Rapid Elasticity" on page 2 as essential characteristics, distinguishing them from the operational goal of reliability/availability).

A. Fiber: Requires the installation of a physical fiber-optic cable network, which is a significant form of infrastructure not present in the described scenario.

B. Cable: Relies on a coaxial cable network, the same used for cable television, which is a form of terrestrial infrastructure that would be absent.

C. DSL: Utilizes existing copper telephone lines to provide an internet connection, a type of infrastructure that is unavailable on unimproved land.

1. Federal Communications Commission (FCC). (n.d.). Types of Broadband Connections. FCC.gov. In the "Satellite" section, it states, "Satellite broadband is another form of wireless broadband and is also useful for serving remote or sparsely populated areas." This confirms its utility where other infrastructure is absent. Retrieved from the official FCC website's consumer guides.

2. Cisco Networking Academy. (2020). IT Essentials v7.0 Curriculum. Chapter 1, Section 1.3.2.5, "WANs". The curriculum describes various WAN connection types, noting that "Satellite service can provide a connection when a wired solution is not available," directly addressing scenarios lacking physical infrastructure.

3. Kurose, J. F., & Ross, K. W. (2021). Computer Networking: A Top-Down Approach (8th ed.). Pearson. In Chapter 1, Section 1.2.1, "Home Access: DSL, Cable, FTTH, Dial-up, and Satellite," the text explains that satellite links are used in locations "where DSL, cable, and fiber-to-the-home are unavailable." This is a standard university-level textbook for computer science and networking courses.

A. DDR5: This is a memory standard defining speed and architecture. While modern, it does not inherently include the error-correction feature required for high availability.

C. DDR4: Like DDR5, this is a memory standard. It specifies the generation of RAM technology but does not, by itself, guarantee error-correction capabilities.

D. Dual-channel: This is a memory architecture that increases data transfer speed by using multiple channels. It enhances performance but does not provide fault tolerance or error correction.

1. University Courseware: Hennessy, J. L., & Patterson, D. A. (2011). Computer Architecture: A Quantitative Approach (5th ed.). Morgan Kaufmann. In Chapter 5, "Memory Hierarchy Design," the text discusses memory reliability, stating, "For servers or large-scale clusters, ECC is a requirement... a single-bit error in a multi-terabyte memory is a near certainty. Hence, virtually all server memory is protected by ECC." (Section 5.5, Dependability, Reliability, and Availability).

2. Vendor Documentation: Intel Corporation. (2021). Intel® Xeon® E-2300 Processor Family Datasheet, Volume 1 of 2. Document Number: 645111-002. On page 21, Section 2.3.1 "Memory Support," it is specified that the processor's Integrated Memory Controller (IMC) supports DDR4 with Error Correction Code (ECC), highlighting its importance for the server-grade processor platform.

3. Academic Publication: Kim, J., & Erez, M. (2009). Adaptive Granularity Memory Systems: A Tradeoff between Storage and Latency. Proceedings of the 36th International Symposium on Computer Architecture (ISCA '09). The paper discusses memory system design for reliability, noting, "Error Correcting Codes (ECC) are widely used to protect main memory from soft errors, especially in servers where reliability is paramount." (Section 1, Introduction, para. 2). DOI: https://doi.org/10.1145/1555754.1555758

A. Clean the print heads: This procedure is used to resolve issues like streaks, faded colors, or missing lines caused by clogged ink nozzles, not misalignment.

C. Replace the ink cartridge: This is done when ink is low or the cartridge is faulty, which typically results in faded prints, incorrect colors, or blank pages.

D. Scan the document: Scanning is an input process for creating a digital copy and is unrelated to troubleshooting the printer's physical output mechanism.

1. Hewlett-Packard (HP) Official Documentation: In the support guide for fixing poor print quality, HP lists "Align the printheads" as the specific step to resolve issues where "text or images are not sharp" or are misaligned.

Source: HP Customer Support, Knowledge Base. "HP DeskJet, ENVY 6000, 6400 printers - Fixing Poor Print Quality," Document c06557959, Step 6: Align the printheads.

2. CompTIA A+ Core 1 (220-1101) Exam Objectives: The official exam objectives explicitly list calibration as a key printer maintenance task that technicians must know how to perform.

Source: CompTIA A+ Core 1 (220-1101) Exam Objectives, Section 2.8 "Given a scenario, perform printer maintenance," bullet point "Calibration."

3. University Courseware/IT Support: Reputable university IT departments document this as a standard troubleshooting step. For example, Indiana University's knowledge base recommends aligning the print head to fix "garbled or misaligned text."

Source: Indiana University, University Information Technology Services (UITS) Knowledge Base. "Troubleshoot printing problems," Document ID: acix, Section: "Troubleshoot print quality."

A. Hub: A hub is a legacy networking device that operates at Layer 1, repeating electrical signals to all connected devices without any signal conversion or filtering.

B. PoE: Power over Ethernet (PoE) is a technology that transmits electrical power along with data on twisted-pair Ethernet cabling; it is not a device for media conversion.

D. NIC: A Network Interface Card (NIC) is a component that enables a computer to connect to a network. While fiber NICs exist, the device described is a standalone media converter for a router.

1. University Courseware: In course materials for telecommunications, the ONT is defined as customer-premises equipment (CPE) for FTTH services. It terminates the fiber optic line and converts optical signals to electrical signals for the customer's LAN.

Source: University of Colorado Boulder, Department of Electrical, Computer & Energy Engineering, ECEN 5653: Introduction to Data Communications, Lecture on Passive Optical Networks (PON). The architecture diagram shows the ONT as the interface between the optical distribution network and the user's home network (router, PC).

2. Vendor Documentation: Major telecommunications equipment vendors describe the ONT as the endpoint in a PON system located at the subscriber's site.

Source: Cisco, "Cisco ASR 9000 Series Aggregation Services Router PON Solution Configuration Guide," Chapter: "PON Solution Overview." The document states, "The Optical Network Unit (ONU), also called Optical Network Terminal (ONT), is located at the subscriber's premises. The ONU provides interface between the customer equipment and the PON."

3. Peer-Reviewed Publication: Academic literature on optical networks consistently identifies the ONT's role as the optical-to-electrical converter at the user end.

Source: Dixit, A., & Lannoo, B. (2012). "A Survey on Passive Optical Network for Long-Reach and High-Capacity Access." IEEE Communications Surveys & Tutorials, 14(3), 729-758. Section III-A, "PON Architecture," describes the ONT as the device that "terminates the PON and presents native service interfaces to the user," which includes Ethernet for data. (DOI: https://doi.org/10.1109/SURV.2011.092311.00121)

B. An APIPA address is a symptom of a DHCP failure; the core best practice for a server is to use a static IP, which avoids reliance on DHCP altogether.

C. The failure to ping indicates a network layer connectivity or name resolution problem, which must be solved before application-layer services can be reached.

D. The scenario provides no information about a secondary NIC, making its status irrelevant to troubleshooting the described connectivity issue.

---

1. Microsoft Corporation. (2021). Configure IPv4 properties. Microsoft Docs. In the section "To configure IPv4 to use a static IP address," the documentation outlines the procedure for setting a static IP, a standard practice for servers to ensure consistent network accessibility. This aligns with the need for a predictable IP for the hosts file entry. (Reference: learn.microsoft.com/en-us/windows-server/networking/technologies/dhcp/dhcp-deploy-w-existing-static-ip)

2. Kurose, J. F., & Ross, K. W. (2021). Computer Networking: A Top-Down Approach (8th ed.). Pearson. Chapter 4, Section 4.3.2, "DHCP: The Dynamic Host Configuration Protocol," contrasts dynamic address assignment with static assignment. The text explains that static assignment is necessary for network elements that need to be reachable at a fixed address, such as servers.

3. University Information Technology Services (UITS), Indiana University. (2023). At IU, when is it appropriate to use a static IP address? UITS Knowledge Base. The document states, "Static IP addresses are necessary for devices that need to be consistently accessible, such as servers (web servers, application servers, etc.)... If you use DHCP for a server, it might be assigned a different IP address after a reboot, which would make it inaccessible to clients trying to reach it at its old address." This directly supports the rationale for the correct answer. (Reference: kb.iu.edu/d/aiau)

A. This describes the function of the Dynamic Host Configuration Protocol (DHCP), which automatically assigns IP addresses and other network configuration parameters to devices.

C. This is the role of authentication protocols and services such as RADIUS, Kerberos, or LDAP, which verify user identities for network access.

D. This describes the function of file transfer protocols like FTP (File Transfer Protocol) or file sharing protocols like SMB (Server Message Block).

1. Mockapetris, P. (1987). RFC 1034: Domain Names - Concepts and Facilities. Internet Engineering Task Force (IETF). Section 2.1, "Name space specifications and terminology," states, "The domain system is a tree-structured name space... The data associated with the names are resource records (RRs). The most common use of the domain system is for names of hosts, which have RRs which hold their IP addresses."

2. Saltzer, J., & Kaashoek, F. (2018). 6.033 Computer System Engineering, Spring 2018 Lecture Notes. Massachusetts Institute of Technology (MIT) OpenCourseWare. Lecture 17, "Naming," Section 17.2, "Domain Name System (DNS)," describes DNS as the system that maps human-readable names to IP addresses.

3. Microsoft Corporation. (2023). Domain Name System (DNS). Microsoft Learn. In the overview section, it states, "Domain Name System (DNS) is one of the industry-standard suite of protocols that comprise TCP/IP, and together the DNS Client and DNS Server provide computer name-to-IP address mapping name resolution services to computers and users."

A. Rapid elasticity – Refers to quick scaling up/down of resources, not to multi-tenant sharing on a single instance.

B. High availability – Concerns fault tolerance and uptime through redundancy, unrelated to hosting multiple tenants together.

D. Metered utilization – Describes pay-per-use billing; it does not provide the mechanism for housing multiple organizations on one VM.

1. NIST Special Publication 800-145, “The NIST Definition of Cloud Computing,” §3, “Resource Pooling,” p.2 – explains multi-tenant sharing of pooled resources.

2. VMware vSphere 7 “Resource Management Guide,” Chapter 1 “Resource Pools and Shares,” pp. 11-12 – details how one host’s resources are divided among many VMs for different customers.

3. MIT OpenCourseWare, 6.828 “Operating System Engineering,” Lecture 9 slides, “Virtualization: Multi-tenancy via shared hardware resources,” slide 4 – shows multiple web servers from separate organizations running on one physical server through a hypervisor.

A. Private: This model offers maximum customization but typically involves higher capital and operational expenditure, which contradicts the goal of saving money.

B. Public: This model is cost-effective but provides limited control over the underlying hardware and infrastructure, failing the customization requirement.

D. Community: This model involves sharing infrastructure among organizations with common goals and is not designed for a single company's specific customization needs.

1. Mell, P., & Grance, T. (2011). The NIST Definition of Cloud Computing (Special Publication 800-145). National Institute of Standards and Technology. Retrieved from https://doi.org/10.6028/NIST.SP.800-145.

Page 3, Section "Deployment Models": Defines Hybrid Cloud as "a composition of two or more distinct cloud infrastructures (private, community, or public)..." This supports the concept of combining models to gain their respective benefits.

2. CompTIA. (2022). CompTIA A+ Core 1 (220-1101) Exam Objectives.

Section 2.5: "Given a scenario, configure and use cloud-based services." This section explicitly lists Public, Private, Hybrid, and Community as required knowledge areas, confirming the question's relevance to the exam domain.

3. Microsoft Azure Documentation. (n.d.). What is hybrid cloud computing? Microsoft.

Overview Section: "Hybrid cloud is a computing environment that connects a company’s on-premises private cloud and third-party public cloud into a single, flexible infrastructure for running the company’s applications and workloads." This vendor documentation confirms the model's purpose of combining environments for flexibility and cost-efficiency.

B. WAN: A Wide Area Network (WAN) spans a very large geographical area, such as a country or the entire globe (e.g., the Internet).

C. LAN: A Local Area Network (LAN) connects devices within a limited area like a home, school, or office building.

D. MAN: A Metropolitan Area Network (MAN) is larger than a LAN but smaller than a WAN, typically covering a city or a large campus.

1. Kurose, J. F., & Ross, K. W. (2021). Computer Networking: A Top-Down Approach (8th ed.). Pearson. In Chapter 1, Section 1.3, the text describes network types by scale, classifying Bluetooth as a technology for Personal Area Networks (PANs).

2. IEEE Standard for Information technology. (2005). IEEE Std 802.15.1-2005 - Part 15.1: Wireless Medium Access Control (MAC) and Physical Layer (PHY) Specifications for Wireless Personal Area Networks (WPANs). The official IEEE standard, which is the basis for classic Bluetooth, explicitly defines it as a technology for Wireless Personal Area Networks. The title and introduction of the standard establish this classification.

3. Forouzan, B. A. (2013). Data Communications and Networking (5th ed.). McGraw-Hill. Chapter 1, Section 1.3 "Networks," categorizes networks by size, defining a PAN as a network for an individual and citing Bluetooth as a primary example of a wireless PAN.

A. Magnetic duster: Toner is primarily composed of plastic and is not significantly magnetic, rendering a magnetic duster ineffective for cleanup.

C. Compressed air: This will aerosolize the fine toner particles, creating a significant respiratory hazard and spreading the contamination over a wider area.

D. Damp cloth: Applying moisture will cause the toner to clump and smear, making the mess worse and posing a risk of water damage to sensitive electronics.

---

1. HP Inc. (Vendor Documentation): In the HP LaserJet Enterprise M607, M608, M609 Service Manual, Section "Clean the printer," it explicitly states, "Use a toner vacuum to clean any toner from inside the printer." It further warns, "CAUTION: Do not use compressed air to clean the printer. Compressed air can cause toner to contaminate the laser/scanner assembly." (Part number: E6B67-90931, Page 219).

2. University of Washington (University Courseware/Documentation): In its IT support documentation regarding printer maintenance, it is a standard best practice to use specialized equipment. The document "Best Practices for Printer and Copier Maintenance" notes that for internal cleaning of toner spills, "a technician will use a toner vacuum designed to filter fine particles and prevent static discharge." (UW IT Connect, Knowledge Base Article KB0018765).

3. IBM Corporation (Vendor Documentation): Service manuals for IBM laser printers consistently specify the correct tools for maintenance. For example, the IBM Infoprint 1000 Family Service Manual directs technicians under "Cleaning Procedures" to "Use a toner vacuum to remove any accumulated toner in the cartridge area. Do not use a standard vacuum cleaner." (Publication Number: S550-0393-02, Chapter 4, Page 12).

A. Near-field communication (NFC) is incorrect because its extremely short operational range (a few centimeters) makes it impractical for scanning inventory across a warehouse.

C. Bluetooth, while used for asset tracking (e.g., BLE beacons), is generally less efficient and scalable for rapidly scanning thousands of individual inventory items compared to dedicated RFID systems.

D. 802.11 (Wi-Fi) is a wireless networking protocol designed for data communication between devices like computers and routers, not for tagging and tracking individual, non-powered inventory items.

1. Want, R. (2006). An Introduction to RFID Technology. IEEE Pervasive Computing, 5(1), 25-33. https://doi.org/10.1109/MPRV.2006.2. (In Section "RFID Applications," the paper details its use in supply-chain management for tracking goods from manufacturing to the point of sale, highlighting its advantage in warehouse settings over barcodes).

2. MIT OpenCourseWare. (2005). MAS.962 Special Topics in Media Technology: Smart Objects, Lecture 10: RFID. Massachusetts Institute of Technology. Retrieved from https://ocw.mit.edu/courses/mas-962-special-topics-in-media-technology-smart-objects-spring-2005/resources/lec10rfid/. (The lecture notes on slides 4-7 and 21-23 compare RFID's capabilities, such as non-line-of-sight and multiple-tag reading, against other technologies, establishing its suitability for inventory applications).

3. Zebra Technologies. (2021). The Next-Generation Warehouse: Five-Year Technology Outlook Report. (This official vendor documentation details the industry-wide adoption of RFID for inventory accuracy and visibility in warehouse operations. Section "Inventory Management," page 6, explicitly identifies RFID as a key technology for automating inventory tracking).

A. Network drive remote access: This typically refers to a VPN or DirectAccess. While it provides access, it requires a constant connection to the office network, which may not be the user's requirement for offline work.

B. Local user account: The user's local account is functioning correctly, as evidenced by their ability to work and access the files while at the office. The problem is related to network connectivity.

C. Remote fileshare permissions: The user can access the files at the office, which confirms their permissions on the fileshare are correct. The issue is access when disconnected, not a permissions problem.

---

1. Microsoft Corporation. (2021). Offline Files overview. Microsoft Learn.

Reference: In the "What is Offline Files?" section, the document states, "The Offline Files feature of Windows makes network files available to a user, even if the network connection to the server is unavailable or slow... When a user is connected to the network, the file access is at online speeds. When a user is disconnected, the files are retrieved from the Offline Files folder at local access speeds. A computer switches to Offline Mode when: The computer is disconnected from the network." This directly supports the use of Offline Files for the scenario described.

2. Princeton University Office of Information Technology. (n.d.). Windows 10: How to make network files or folders available offline. OIT KnowledgeBase.

Reference: Article ID 1060, in the "Make a network file or folder available offline" section. The guide instructs, "This feature is useful for users who need to access files on the network when they are not connected to the network." This university documentation validates that Offline Files is the standard solution for making network files accessible when disconnected.

3. Tanenbaum, A. S., & Wetherall, D. J. (2011). Computer Networks (5th ed.). Pearson Education.

Reference: Chapter 8, Section 8.6.3, "File Caching." The text discusses the principle of client-side caching to improve performance and provide access to data during network disconnections. It explains, "Caching is a key technique for improving performance... If the client machine has a local disk, a copy of a remote file can be stored on the disk. When the file is opened, a check has to be made to see if the local copy is still valid. If it is, the open can be done locally." This academic principle underpins the functionality of Windows Offline Files.

B. 850W: This wattage is excessive and intended for high-performance gaming PCs with powerful, dedicated graphics cards and multi-core CPUs.

C. 1,000W: This is an enthusiast-grade PSU for systems with multiple high-end components or significant overclocking, making it extreme overkill for this build.

D. 2,000W: This is a specialty or server-grade PSU wattage, completely inappropriate and nonsensical for a basic, low-power desktop computer.

1. CompTIA A+ Core 1 (220-1101) Exam Objectives, Version 5.0.

Section 1.6: "Given a scenario, select and install appropriate components for a custom PC configuration..." This objective requires the candidate to match component selection, including the power supply, to the user's needs (e.g., a budget PC).

Section 1.8: "Explain the functions and characteristics of power supplies." This includes understanding wattage ratings and how to select an appropriate one based on the power requirements of the system's components.

2. Intel® Core™ Processors Datasheet, Volume 1 of 2.

Section 7.1, "Power and Current Specifications": Documentation for a typical dual-core budget CPU, such as an Intel® Celeron® Processor G6900, lists the Processor Base Power at 46W. This demonstrates the low power consumption of a key component in the described build.

3. Kingston Technology Company, NV2 NVMe™ PCIe SSD Product Datasheet.

Specifications Table: The power consumption for a typical budget SSD is listed as approximately 3.3W at its maximum read/write load and much lower at idle. This confirms that storage contributes minimally to the overall power budget.

4. Patterson, D. A., & Hennessy, J. L. (2017). Computer Organization and Design: The Hardware/Software Interface (5th ed.). Morgan Kaufmann.

Chapter 1, Section 1.6, "Trends in Cost": This section discusses the relationship between component choice, cost, and system purpose. A fundamental principle in system building is matching the power supply capacity to the actual system load to manage cost and thermal output, which is a core concept for a "budget PC" scenario. A 400W PSU aligns with the low cost and low power draw of the specified components.

B. Physical address: The physical (MAC) address operates at Layer 2 for local network communication and is not used for resolving domain names.

C. Subnet mask: The subnet mask is correctly configured for the network. An incorrect mask would cause general connectivity problems, not a specific name resolution failure.

D. IPv4 address: The client's IPv4 address is valid for the configured subnet and is not the cause of a hostname resolution error.

E. Default gateway: The default gateway is used for routing traffic to other networks. While essential for overall connectivity, its misconfiguration would not produce this specific DNS error.

1. Microsoft Corporation. (2023). Troubleshooting domain join error messages. Microsoft Learn. Retrieved from https://learn.microsoft.com/en-us/windows-server/identity/ad-ds/deploy/troubleshooting-domain-join-error-messages.

Reference Specifics: In the table of error messages, the cause for "An attempt to resolve the DNS name of a domain controller in the domain being joined has failed" is listed as: "Verify that this client is configured to reach a DNS server that can resolve DNS names in the target domain." This directly confirms the issue is DNS configuration.

2. Microsoft Corporation. (2009). How DNS Support for Active Directory Works. Microsoft TechNet. Retrieved from https://learn.microsoft.com/en-us/previous-versions/windows/it-pro/windows-server-2003/cc781627(v=ws.10).

Reference Specifics: The section "Locating a Domain Controller" explains that a client computer locates a domain controller by querying DNS for a service (SRV) resource record. This process fails if the client's configured DNS server does not host or cannot resolve records for the target domain.

A. Bluetooth: This is a wireless technology. The user's requirement is for a headset that can be physically connected.

B. DVI: The Digital Visual Interface (DVI) is a standard used exclusively for transmitting video signals to a display and does not support audio.

C. Thunderbolt: While Thunderbolt ports can transmit audio data (often as part of a video signal), it is a high-performance interface primarily for storage and displays, not a standard, direct connection for a typical headset.

1. Intel Corporation. (n.d.). What Is a USB Port? Intel. Retrieved from the official Intel website. In the section "What does a USB port do?", it states, "USB ports can be used to connect a variety of devices, including... headsets." This document confirms USB as a standard interface for audio peripherals.

2. Dell Inc. (2024). A Guide to the External Ports and Connectors on a Dell Computer. Dell Knowledge Base, Article 000133329. In the sections describing port types, USB is identified for connecting peripherals, while DVI is specified for video output only. This official vendor documentation distinguishes the primary functions of these ports.

3. Saltzer, J. H., & Kaashoek, M. F. (2009). Principles of Computer System Design: An Introduction. Morgan Kaufmann. In Chapter 6, "The Hardware/Software Interface," Section 6.4.2 discusses I/O buses. It describes the Universal Serial Bus (USB) as a versatile, host-controlled bus for attaching a wide range of low- and medium-speed peripherals, which includes audio devices like headsets.

B. Made sure the replacement drive was compatible

This is a resolution step taken after troubleshooting has concluded that the drive needs replacement.

D. Reseated the HDD connector

This action addresses a potential connection problem, which typically results in the drive not being detected at all, rather than appearing as corrupt.

E. Increased the page file size

The page file is related to virtual memory management and has no connection to drive corruption or mechanical failure.

F. Updated the firmware

While firmware can cause issues, it is not a standard initial step for diagnosing the symptoms of file corruption and potential mechanical failure.

1. Microsoft Corporation. (2023). chkdsk. Microsoft Learn. Retrieved from https://learn.microsoft.com/en-us/windows-server/administration/windows-commands/chkdsk. The documentation states, "Checks the file system and file system metadata of a volume for logical and physical errors." This supports the use of CHKDSK to identify a "corrupt" drive.

2. Purdue University, College of Engineering. (n.d.). Hard Drive Failure, Prevention, and Troubleshooting. ECN Knowledge Base. In the section "Troubleshooting a Hard Drive," the guide lists "Run a diagnostic such as Checkdisk (chkdsk)" and "Check the S.M.A.R.T. status" as primary steps for diagnosing hard drive issues. (Reference: Specific troubleshooting guides within the Purdue ECN documentation).

3. University of Washington, Paul G. Allen School of Computer Science & Engineering. (2017). CSE 351: The Hardware/Software Interface, Section 7, Disks. Courseware. In the lecture notes on disks, S.M.A.R.T. is described as a technology for "predicting catastrophic disk failure," which directly relates to diagnosing a "possible mechanical failure." (Reference: Lecture notes on Storage and Disks).

B. RAID 1 (mirroring) provides redundancy at the cost of 50% storage utilization and does not offer the same write performance boost as RAID 0.

C. RAID 5 (striping with parity) incurs a write performance penalty due to parity calculations and uses one drive's capacity for redundancy, failing the "maximum utilization" requirement.

D. RAID 10 (a stripe of mirrors) is expensive, requiring a minimum of four drives, and has only 50% storage utilization, violating the "minimal cost" and "maximum utilization" constraints.

1. Patterson, D. A., Gibson, G., & Katz, R. H. (1988). A case for redundant arrays of inexpensive disks (RAID). In Proceedings of the 1988 ACM SIGMOD international conference on Management of data (pp. 109-116). Section 3, "RAID: High Performance, Reliable Secondary Storage," describes the fundamental principles of striping for performance (Level 0) versus mirroring for reliability (Level 1). DOI: https://doi.org/10.1145/50202.50214

2. Carnegie Mellon University, Parallel Data Laboratory. (2019). An Introduction to RAID. Retrieved from The RAIDBook. In the "RAID 0: Striped Disk Array without Fault Tolerance" section, it is stated, "RAID 0 is useful in situations where performance and capacity, rather than reliability, are the primary concerns." The sections on RAID 1, 5, and 10 explicitly detail their costs in terms of storage overhead and performance penalties.

3. University of Texas at Austin, Texas Advanced Computing Center. Storage Systems and I/O. Courseware. The module on RAID levels describes RAID 0 as having "No redundancy" and "High I/O performance," while noting the storage inefficiency and performance characteristics of RAID 1, 5, and 10 that make them unsuitable for the question's specific requirements.

A. Disabling Bluetooth would not address the observed high network (cellular/Wi-Fi) utilization, which is the most likely cause of the severe battery drain.

B. Connecting the smartphone to a Wi-Fi network only changes the connection medium; it does not stop the underlying process causing the high data usage.

D. Updating the mobile OS is a more complex and lengthy procedure that should be performed only after simpler steps, like a restart, have failed to resolve the issue.

1. Google LLC, Android Help Center. In the troubleshooting guide for an unresponsive device, the first recommended step is to restart the phone. This establishes the principle of rebooting as a primary action for software-related malfunctions.

Source: Google Android Help, "Troubleshoot a phone that freezes or is unresponsive," Step 1: Restart your phone.

2. Apple Inc., Apple Support. For troubleshooting misbehaving applications, which can cause performance and battery issues, restarting the device is a standard procedure recommended after attempting to close the specific app.

Source: Apple Support, "If an app on your iPhone or iPad stops responding, closes unexpectedly, or won’t open," HT201398, Step 3: Restart your device.

3. Carnegie Mellon University, Information Security Office. University IT guidelines for mobile device troubleshooting list restarting the device as a primary step for resolving general performance problems, which include issues like battery drain caused by software faults.

Source: Carnegie Mellon University, "Mobile Device Troubleshooting Guidelines," Section: "General Troubleshooting Steps," Step 1.

B. Replace the monitor.

This is a premature and costly step. Hardware replacement should only be considered after ruling out simpler environmental or power-related causes.

C. Open the display settings on the computer.

A software or configuration issue is less likely, as the problem's onset directly correlates with a physical change (the addition of the heater).

D. Ensure a VGA cable is connected properly.

While checking cabling is a valid step, the most probable cause is the newly introduced heater. The "what has changed" principle dictates investigating the heater first.

---

1. CompTIA A+ Core 1 (220-1101) Exam Objectives. Section 5.1, "Given a scenario, use the best practice methodology to resolve problems." This section outlines the troubleshooting process, which includes: "1. Identify the problem. 2. Establish a theory of probable cause (question the obvious)." The most obvious change in this scenario is the heater.

2. University of Washington, IT Connect. "Troubleshooting IT." This guide for IT professionals states, "What has changed since the last time it worked? This is the most important question you can ask when you start troubleshooting." This principle directly supports identifying the heater as the probable cause.

3. Dell Inc. Knowledge Base. Article ID: 000125799, "How to Troubleshoot Display or Video Issues on a Dell Monitor." In the troubleshooting steps, it advises to "Check for any possible interference," noting that devices like speakers, fans, or fluorescent lights can cause screen issues, which is analogous to the potential EMI from a heater. It also prioritizes checking the power source.

B. Incompatible video driver: A video driver issue would affect the data being sent to the display, typically causing artifacts, incorrect resolution, or a completely blank screen with no image at all.

C. Incorrect input source: This would mean the laptop is configured to output video to an external display, resulting in no signal being sent to the internal panel and thus no faint image.

D. Burned-out bulb: While a burned-out CCFL bulb would also cause a backlight failure, the inverter is a complex electronic component that is also a very frequent point of failure for this specific symptom.

1. Dell Inc. Official Documentation: Dell Knowledge Base Article 000131347, "How to Troubleshoot Display or Video Issues on a Dell Laptop." In the section "Troubleshoot a blank or black screen," the guide states, "If the faint image is seen on the screen, the issue could be with the LCD inverter or the LCD backlight lamp of the LCD screen." This confirms that the inverter is a primary suspect for this symptom.

2. University Courseware: University of Washington, CSE 466: Computer Systems Architecture & Design, Lecture on "Embedded Systems: Displays." Course materials describe the architecture of LCDs, noting that CCFL-based systems require a high-voltage inverter to drive the backlight, and failure of this component results in a non-illuminated but otherwise functional display.

3. HP Inc. Official Documentation: HP Customer Support - Knowledge Base, Document: c01997899, "Troubleshooting a Notebook LCD Panel Issue (Windows 10, 8, 7)." In the section "Image on screen is dim," the guide identifies potential causes as "The LCD inverter has failed" or "The LCD backlight bulb has failed," listing the inverter as a key component to investigate.

A. Efficiency rating: This indicates how effectively the PSU converts AC power to DC power, affecting electricity costs and heat output, but not its fundamental ability to power the system if the wattage is sufficient.

B. Heat dissipation: This is a byproduct of the PSU's efficiency and load, not a primary selection criterion itself. A PSU with the correct wattage and form factor will manage its own heat.

E. Fan type: This influences the PSU's noise level and operational lifespan but does not determine its compatibility or power delivery capability for the workstation's components.

F. Modular cabling: This is a convenience feature that improves cable management and airflow within the case but is not a requirement for the PSU to function and support the system.

1. CompTIA A+ Core 1 (220-1101) Exam Objectives, Section 1.5, "Given a scenario, select and install components for a custom PC configuration." This objective explicitly lists "Wattage" and "Form factors" (ATX, Micro-ATX, SFX) as essential characteristics to consider when selecting a power supply.

2. Patterson, D. A., & Hennessy, J. L. (2017). Computer Organization and Design: The Hardware/Software Interface (5th ed.). In Chapter 1, "Computer Abstractions and Technology," the text discusses the physical assembly of a computer. It implicitly supports the need for components to physically fit (form factor) and be supplied with adequate power (wattage) to function as an integrated system (Section 1.4, "Under the Covers").

3. University of Illinois, Department of Computer Science. CS 241: System Programming Course Notes. Lecture notes on "The Hardware/Software Interface" typically cover PC component selection, emphasizing that the power supply's capacity (wattage) must meet or exceed the sum of the components' power requirements and that its physical specification (form factor) must match the chassis.

A. Installing an SSD: This would only speed up the existing inefficient process of formatting and reinstalling, not change the fundamental workflow.

C. Disabling hyperthreading: This is a CPU performance feature; disabling it is irrelevant to system reconfiguration and would likely degrade performance.

D. Enabling hardware acceleration: This offloads tasks to specialized hardware to improve application performance, but does not address the efficiency of resetting the test environment.

1. CompTIA A+ Core 1 (220-1101) Exam Objectives, Section 1.6, "Explain the purpose and uses of virtualization and cloud computing." This section explicitly lists "Sandbox" and "Virtual machines (VMs)" as key concepts, highlighting their use for creating isolated environments for testing and development.

2. Microsoft Corporation, "Windows Sandbox," Microsoft Docs. This official vendor documentation states, "Windows Sandbox provides a lightweight desktop environment to safely run applications in isolation... When Windows Sandbox is closed, all software and files and the state are deleted." This directly describes the solution to the developer's problem of needing a clean environment for each test.

3. Saltzer, J. H., & Kaashoek, M. F. (2009). Principles of Computer System Design: An Introduction. Morgan Kaufmann. In Chapter 9, "Virtual Machines," the text discusses how VMs provide isolation and the ability to "roll back the state of a virtual machine to a previously saved checkpoint," which is the mechanism that makes sandboxed testing efficient.

A. Redundant hardware: This provides high availability and fault tolerance for component failures (e.g., power supplies, NICs) but does not protect data if the entire server or site is destroyed.

B. UPS: An Uninterruptible Power Supply (UPS) protects against power outages and surges, preventing data corruption from improper shutdowns, but offers no protection against other hardware failures.

D. RAID: Redundant Array of Independent Disks (RAID) protects against the failure of individual hard drives within the server but does not safeguard data from a complete server failure or site-wide disaster.

1. National Institute of Standards and Technology (NIST). (2010). Special Publication 800-34 Rev. 1, Contingency Planning Guide for Federal Information Systems.

Section 3.4.2, "Backup and Storage Strategies," emphasizes the necessity of storing backup media at an off-site location. It states, "The storage facility should be located at a sufficient distance from the primary site to reduce the likelihood of being affected by the same event (e.g., fire, flood, tornado, hurricane, earthquake)." A cloud-based backup is a modern implementation of this core principle.

2. VMware, Inc. (2021). vSphere Availability Guide, ESXi 7.0 U2, vCenter Server 7.0 U2.

Chapter 1, "vSphere Availability," distinguishes between high availability solutions like vSphere HA (which restarts VMs on other hosts after a hardware failure) and data protection solutions (backups). The guide implicitly clarifies that features like hardware redundancy provide service continuity but are not a substitute for backups, which are required for disaster recovery and data protection.

3. Saltzer, J. H., & Kaashoek, M. F. (2009). Principles of Computer System Design: An Introduction. MIT.

Chapter 5, "Reliability," discusses the distinction between techniques that handle faults (like RAID and redundant components) and those that handle disasters. It explains that while RAID can recover from disk failures, backups are necessary to recover from failures that corrupt or destroy the entire storage system, reinforcing that backups provide a higher level of data protection against catastrophic hardware failure.

The optimal configuration must balance the requirements for speed, fault tolerance, and capacity.

1. RAID Level Selection: RAID 10 (a stripe of mirrors) is the best choice. It provides high I/O performance by striping data across mirrored sets (satisfying the "fastest speed" requirement for video editing) and offers excellent redundancy by mirroring data (addressing "disk failure without any downtime"). While RAID 6 offers higher fault tolerance (surviving two disk failures), it incurs a significant write performance penalty, making it unsuitable for a high-throughput video-editing workload.
2. Drive Type: SSDs are selected over HDDs for their vastly superior read/write speeds, which directly addresses the "fastest speed" requirement.
3. Capacity Calculation: RAID 10 requires a minimum of four disks. The usable capacity is 50% of the total raw capacity. To achieve 2TB of usable space, four 1TB drives are needed ((4 drives/2)×1TB=2TB).

This configuration provides the best combination of performance and redundancy for the specified workstation.

Arpaci-Dusseau, R. H., & Arpaci-Dusseau, A. C. (2018). Operating Systems: Three Easy Pieces. Arpaci-Dusseau Books.

Chapter 39.5, "RAID-10: A Stripe of Mirrors", explains the structure and benefits: "RAID-10... offers the performance benefits of striping data across multiple disks (like RAID-0) and the reliability benefits of mirroring (like RAID-1)... For each write, the system must send the request to four disks... Thus, RAID-10 provides high performance, particularly for random I/O workloads such as those found in database and other high-performance applications." This supports choosing RAID 10 for performance-critical workloads.

Intel Corporation. (2020). Intel® Virtual RAID on CPU (Intel® VROC) and Intel® Rapid Storage Technology Enterprise (Intel® RSTe) Comparison. Performance Brief.

Page 5, "RAID 10 – Mirrored and Striped": The document states, "RAID 10 has the advantage of fast reads and writes..." and notes its high redundancy. This official vendor documentation highlights RAID 10's suitability for high-speed, fault-tolerant applications like a video-editing workstation.

Patterson, D. A., & Hennessy, J. L. (2017). Computer Organization and Design RISC-V Edition: The Hardware Software Interface. Morgan Kaufmann.

Section 5.4, "Dependability, Reliability, and Availability": In its discussion of RAID levels, the text notes the performance trade-offs. It explains that RAID 6 "has a much higher write penalty than RAID 5," which is even more pronounced when compared to RAID 10. For workloads with many small writes, common in editing, "RAID 1+0 (or 10) is the preferred choice." This confirms that RAID 6's write penalty makes it less suitable for this scenario, despite its higher redundancy.

A. Serial links use DB-9, DB-25, or RJ-45 connectors—not threaded coax F-type.

C. Laptop power adapters employ proprietary barrel plugs or USB-C PD, not coaxial F-type connectors.

D. Electrical service conductors terminate on lugs/breakers; F-type is rated for RF, not high-voltage AC wiring.

1. Cisco Networking Academy. “Introduction to Networks v7.0,” Ch. 4, Sec. 4.2.1.1 Coaxial Cable Connectors, Figure 4-16 (shows F-type for cable TV/Internet).

2. MIT OpenCourseWare 6.02 “Digital Communication Systems,” Lec 2 slides 11–13 (discusses RG-6 coax with F-type connectors for broadband).

3. Comcast Cable Communications. “Residential Premises Installation Manual,” Rev 2.4, §3.1, p. 14–15 (specifies RG-6 drop cable terminated with F-type connectors for DOCSIS service).

A. Update the Ethernet driver: This is a software-based solution. It cannot fix a physical hardware failure like a broken RJ45 port.

C. Replace the NIC: On most laptops, the Network Interface Card (NIC) is integrated into the motherboard. Replacing it is a major, time-consuming repair, not an immediate fix.

D. Resolder the network connector: This is a component-level repair requiring specialized skills and equipment. It is not a quick or standard procedure for immediate service restoration.

---

1. CompTIA A+ Core 1 (220-1101) Exam Objectives, Version 5.0, Section 3.2, "Given a scenario, troubleshoot wired and wireless networks." This objective covers identifying and resolving connectivity issues. When a wired connection (RJ45) fails due to hardware, using an alternative like wireless is a standard troubleshooting step to restore service.

2. University of Michigan, Information and Technology Services (ITS) Documentation, "Troubleshooting Wired Network Connections." In standard IT support procedures, when a physical port failure is diagnosed, the immediate action to restore user productivity is to employ an alternative connection method. For a laptop, this is typically the wireless interface. The guide implicitly supports this by treating wired and wireless as separate, viable connection paths.

3. Dell Inc. Knowledge Base, Article ID: 000124311, "How to Troubleshoot Wired Network Problems on Your Dell Laptop." This official vendor documentation outlines steps for diagnosing a faulty wired connection. In a support context, once a hardware fault is confirmed, the immediate workaround is to use an alternative like Wi-Fi, deferring the hardware repair.

B. The laptop's video card has failed: A failed video card would typically result in no signal, severe visual artifacts (like lines or incorrect colors), or system crashes, not a consistently distorted image.

C. The projector's bulb is burned out: A burned-out bulb would result in no light output, meaning there would be no image at all, rather than a distorted one.

D. The display brightness needs to be adjusted: Incorrect brightness settings would make the image too dim or too bright but would not alter its shape or cause geometric distortion.

1. University of Wisconsin-Madison, Division of Information Technology (DoIT) KnowledgeBase. In the troubleshooting guide for classroom projectors, it states: "If the image on the screen appears stretched or distorted, the aspect ratio may be incorrect. Use the projector remote to change the aspect ratio. The 'Aspect' button may be on the remote itself, or it may be in the projector menu." (Document ID: 8511, Section: "Troubleshooting Projector Image Issues").

2. Epson PowerLite Projector User's Guide. In the "Solving Image Problems" troubleshooting section, a common issue listed is "The image is stretched..." The recommended solution is to "Press the [Aspect] button on the remote control to select the correct aspect ratio" or adjust the "Aspect" setting in the projector's menu system. (Reference: Epson PowerLite 1780W/1781W/1785W/1795F User's Guide, Page 88, "Image Problems").

3. Andrews, J. (2022). A+ Guide to IT Technical Support (11th ed.). Cengage Learning. In the context of display troubleshooting, the text explains that the aspect ratio (e.g., 4:3, 16:9, 16:10) is a critical display setting. A mismatch between the native resolution/aspect ratio of the display and the signal being sent can cause the image to be distorted, stretched, or have black bars. (Chapter 8: Supporting Windows, Section: "Display Settings").

A. The pictures do not have a classification flag set.

Security policies typically restrict the movement of classified data, not unclassified personal files, making this an unlikely cause for the block.

B. The drive permissions are insufficient.

This would be a local file system issue on the home drive and would not be dependent on the device's physical location (work vs. home).

D. Drivers are incorrectly installed.

A driver issue would likely prevent the external drive from functioning correctly in all locations, not just selectively at home.

---

1. Microsoft Corporation. (n.d.). Android Enterprise device settings to allow or restrict features on corporate-owned devices using Intune. Microsoft Learn.

Section: Device restrictions > General > Block external storage.

Content: This official vendor documentation details how an MDM solution (Microsoft Intune) can enforce policies to "Block users from using external storage on their devices." These policies can be applied conditionally, aligning with the scenario where peripheral access is managed differently based on context (e.g., corporate vs. personal profile, network location).

2. Pattabiraman, K. (2022). Lecture 20: Mobile Security. Carnegie Mellon University, Course 18-631: Information Security and Privacy.

Page: Slide 23 ("Mobile Device Management (MDM)").

Content: University courseware from Carnegie Mellon University explains that MDM solutions "enforce security policies on mobile devices," which includes "disabling hardware features (e.g., camera, USB port)." This supports the concept of a central policy managing peripheral access.

3. Tysowski, P. K., & Memon, N. (2014). Mobile Device Management: A Security and Privacy Perspective. In Mobile Security and Privacy (pp. 203-223). Springer, Cham.

DOI: https://doi.org/10.1007/978-3-319-04936-39

Section: 9.3.1 Policy Enforcement.

Content: This peer-reviewed book chapter discusses how MDM frameworks enforce security policies, including restrictions on device peripherals like USB storage. It notes that policies can be dynamically applied based on various contexts to mitigate security risks such as data exfiltration.

A. Encryption cipher: An incorrect or incompatible encryption cipher would typically prevent a user from connecting at all, rather than causing slow performance and intermittent drops.

C. Number of connected devices: While an excessive number of devices can slow down a network by sharing bandwidth, it is less likely to be the primary cause of frequent connection drops for all users.

D. Antenna type: The antenna type affects the signal's range and coverage pattern. It is a static hardware configuration and would not typically cause intermittent performance degradation unless it was recently changed or damaged.

1. Kurose, J. F., & Ross, K. W. (2017). Computer Networking: A Top-Down Approach (7th ed.). Pearson.

Section 6.3.2, "The IEEE 802.11 Wireless LAN," discusses sources of interference in 802.11 networks. It explains that other access points and various electronic devices operating in the same frequency band can interfere with each other, leading to decreased throughput and signal degradation.

2. Cisco. (2018). Radio Frequency Interference. Cisco Press.

In the chapter on troubleshooting wireless LANs, the documentation states, "Symptoms of RF interference can include low throughput and intermittent connectivity... Interference is caused by other RF-producing devices that operate in the same frequency range as the wireless LAN." This directly aligns with the scenario.

3. Tanenbaum, A. S., & Wetherall, D. J. (2011). Computer Networks (5th ed.). Prentice Hall.

Section 4.3, "The Wireless LANs," details the 802.11 protocol and the challenges of the wireless medium. It explains that co-channel and adjacent-channel interference are significant factors that degrade performance, causing collisions and retransmissions, which manifest as slow speeds and unstable connections.

A. Check the device for updates: While an outdated OS or application could have a bug causing high resource usage, malware is a more direct and common cause for such severe, persistent symptoms.

C. Check the device for liquid damage: Liquid damage can cause short-circuiting and heat, but this is a hardware-level fault. Standard troubleshooting methodology prioritizes less invasive software checks before suspecting and inspecting for physical damage.

D. Check the device's charging adapter: A faulty charging adapter would impact how the device charges but would not cause the device to run hot and drain its battery quickly during normal operation.

1. University of California, Berkeley - Information Security Office. In a guide on securing mobile devices, it lists "Device is slow, crashes, or runs hot" and "Battery drains quickly" as common signs that a device may be infected with malware.

Source: UC Berkeley Information Security Office, "Mobile Device Security," Signs of Malware section.

2. Federal Trade Commission (FTC). The FTC, a U.S. government agency, advises consumers that a sign of malware on a mobile phone is that the "battery drains quickly." This is because malware can run constantly in the background, consuming power.

Source: FTC Consumer Advice, "How to Recognize and Report Spam Text Messages," section "What to do if you think you have malware on your phone."

3. Spreitzenbarth, M., et al. (2013). Systematic Classification of Android Malware and Evasion Techniques. This academic paper discusses the behavior of mobile malware. It notes that malicious activities, such as data exfiltration or running unauthorized processes, lead to increased resource consumption, which manifests as decreased battery life and potential overheating.

Source: Proceedings of the 6th ACM Conference on Security and Privacy in Wireless and Mobile Networks, p. 97. DOI: https://doi.org/10.1145/2462096.2462111

A. This describes leasing physical assets (vehicles), which is a form of hardware rental or "Hardware as a Service," not a software subscription.

C. This is an example of a telematics or emergency response service, which may use software but is not a direct subscription to a software application itself.

D. This is a contract for professional services to create a custom product (a website), not a subscription to use a pre-existing software application.

1. Mell, P., & Grance, T. (2011). The NIST Definition of Cloud Computing (NIST Special Publication 800-145). National Institute of Standards and Technology.

Page 3, Section "Service Models": Defines Software as a Service (SaaS) as: "The capability provided to the consumer is to use the provider’s applications running on a cloud infrastructure... The consumer does not manage or control the underlying cloud infrastructure including network, servers, operating systems, storage, or even individual application capabilities..." This directly supports the scenario in option B, where the accountant uses the provider's tools without managing the infrastructure.

2. Armbrust, M., Fox, A., Griffith, R., Joseph, A. D., Katz, R., Konwinski, A., ... & Zaharia, M. (2009). Above the Clouds: A Berkeley View of Cloud Computing (Technical Report No. UCB/EECS-2009-28). University of California, Berkeley.

Page 2, Section 2.1: Describes SaaS applications as being accessed through a web browser, with the most widely known example being salesforce.com. It states, "SaaS is the most widely known of the three services." The scenario of an accountant using subscription-based tools aligns with this academic definition of using hosted applications for business functions.

B. Installing firmware updates on Wireless Access Points (WAPs) is a network-wide change that is disruptive and unlikely to be the cause for a single device's connection failure.

C. Increasing the router's signal strength is a network-level adjustment that should only be considered after verifying that a weak signal is the actual problem, not as a first step.

D. Resetting the router is a drastic measure that would disconnect all users and should be treated as a last resort after all other possibilities have been exhausted.

1. CompTIA A+ Core 1 (220-1101) Exam Objectives, Section 2.1, "Given a scenario, apply the best practice methodology to resolve problems." The methodology begins with "1. Identify the problem," which involves checking the local system's configuration before escalating to broader network changes. This establishes the principle of starting with the most likely and localized cause.

2. Microsoft Corporation, "Fix Wi-Fi connection issues in Windows," Official Windows Support Documentation. The documented troubleshooting steps begin with client-side actions: "1. Run the Network troubleshooter," "2. Make sure Wi-Fi is on," and checking settings within the operating system before suggesting actions related to the router or modem. This aligns with checking OS network settings first.

3. Carnegie Mellon University, "Troubleshooting Wireless," Computing Services Documentation. The university's official IT support guide for troubleshooting wireless issues instructs users to begin with steps on their own device, such as "Check your physical wireless switch," "Forget the wireless network and reconnect," and "Check for an IP address," all of which fall under reviewing the OS network settings.

B. DNS is used for name resolution, not routing. DHCP is for IP assignment, not name resolution. This option reverses and misstates the roles.

C. DNS resolves names to both public and private IP addresses. DHCP most commonly assigns private IP addresses but is not restricted to them.

D. Routing traffic between networks is the function of a router, not DNS. DHCP assigns addresses within a subnet, it does not allocate the subnets themselves.

1. Internet Engineering Task Force (IETF) RFC 1034, "DOMAIN NAMES - CONCEPTS AND FACILITIES," P. Mockapetris, November 1987. Section 2.1, "Name space specifications and terminology," states that the domain system's purpose is to map domain names to data, such as host addresses. This supports the "address translation" function of DNS.

2. Internet Engineering Task Force (IETF) RFC 2131, "Dynamic Host Configuration Protocol," R. Droms, March 1997. The Abstract (Section 1) states, "The Dynamic Host Configuration Protocol (DHCP) provides a framework for passing configuration information to hosts on a TCP/IP network... DHCP... [adds] the capability of automatic allocation of reusable network addresses and additional configuration options." This confirms DHCP's role in IP address assignment.

3. Microsoft Corporation, "DHCP basics," Microsoft Learn, October 4, 2023. The document states, "Dynamic Host Configuration Protocol (DHCP) is a client/server protocol that automatically provides an Internet Protocol (IP) host with its IP address and other related configuration information such as the subnet mask and default gateway."

4. Kurose, J. F., & Ross, K. W., "Computer Networking: A Top-Down Approach (8th Edition)." Pearson. Chapter 2, Section 2.5, "The Domain Name System," describes DNS as a "distributed database implemented in a hierarchy of DNS servers" that translates hostnames to IP addresses. Chapter 4, Section 4.4.2, "The Dynamic Host Configuration Protocol (DHCP)," details how DHCP allows a host to automatically obtain an IP address from a server.