System requirements are categorized into functional and non-functional types. Security requirements are a critical category of non-functional requirements that define the constraints and measures needed to protect a system and its data from malicious or accidental threats. The act of "preventing unauthorized access" is a fundamental security objective aimed at ensuring data confidentiality and integrity. Therefore, this requirement is explicitly classified as a security requirement, which specifies the rules, access controls, and protective functions the system must implement.

A. Design: Design requirements describe how the system will be implemented (e.g., architecture, platform), not the security policies it must enforce.

B. Accessibility: Accessibility requirements ensure the system is usable by people with disabilities, a concern separate from preventing unauthorized data access.

D. User needs: While users need their data to be secure, "user needs" describe tasks users must perform, whereas security is a system-level constraint that protects all assets.

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1. Sommerville

I. (2016). Software Engineering (10th ed.). Pearson. In Chapter 4

Section 4.2.2

"Non-functional classifications

" security requirements are defined as a primary category that constrains system functions to protect against threats. Preventing unauthorized access is a core example.

2. Glinz

M. (2007

October). On Non-Functional Requirements. 15th IEEE International Requirements Engineering Conference. This paper classifies security as a key non-functional requirement concerning "resistance of a system against attacks" and "protection of data against unauthorized access" (Section 3.2

Table 1). DOI: 10.1109/RE.2007.55

3. MIT OpenCourseWare. (2013). 6.033 Computer System Engineering

Lecture 15: Security. Massachusetts Institute of Technology. The lecture materials define system security goals

with the first being confidentiality

which is explicitly about preventing the unauthorized release of information (i.e.

unauthorized access).

A computer system is the correct term for a complete, functional unit comprising all necessary hardware and software components. This includes the central processing unit (CPU), memory, storage devices, input/output peripherals (hardware), as well as the operating system and application programs (software). These elements are designed to work in concert to process data and execute tasks, thereby meeting the computational needs of a user. The other options represent individual components, not the entire collection.

A. A hard drive: This is a single hardware component used for long-term data storage; it is not a complete collection of hardware and software.

B. An operating system: This is the core software that manages hardware resources, but it is only one part of the software component of a computer system.

D. A motherboard: This is a primary circuit board (hardware) that connects other hardware components but does not include software or peripherals.

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1. Patterson

D. A.

& Hennessy

J. L. (2017). Computer Organization and Design: The Hardware/Software Interface (5th ed.). Morgan Kaufmann. In Chapter 1

Section 1.3

the text describes a computer system as being composed of layers of hardware and software

from the application software down to the physical hardware

all working together.

2. Brookshear

J. G.

& Brylow

D. (2015). Computer Science: An Overview (12th ed.). Pearson. Chapter 2

"Computer Architecture

" defines a computer system as an integrated set of hardware and software components designed to perform computations.

3. Virginia Tech

Department of Computer Science. (n.d.). CS 1114: Introduction to Software Design

Module 1: Computer Systems. The course material defines a computer system as a set of integrated devices that input

output

process

and store data

explicitly stating it is comprised of both hardware and software.

The hierarchical database model organizes data in a tree-like structure. In this model, data is stored as records which are connected to one another through links. Each record is a collection of fields, with each field containing only one value. A record in the hierarchy is referred to as a node or a segment. The top-most node is the root, and every other node has exactly one parent, while a parent can have multiple children. This one-to-many relationship from parent to child is the defining characteristic of the hierarchical model.

A. Embedded: This term describes how a database is deployed (integrated within an application), not the logical data model or structure it uses.

B. Flat file: A flat file database stores data in a single table with no structured, hierarchical relationships between records.

C. Family file: This is not a standard, recognized term for a type of database model in information technology.

1. Elmasri

R.

& Navathe

S. B. (2017). Fundamentals of Database Systems (7th ed.). Pearson. In Chapter 1

Section 1.5

the text describes the hierarchical model: "In the hierarchical model

data are organized into a tree-like structure. The model represents a one-to-many relationship between a parent and its children segments."

2. Silberschatz

A.

Korth

H. F.

& Sudarshan

S. (2010). Database System Concepts (6th ed.). McGraw-Hill. Appendix E (Legacy Database Systems) discusses the hierarchical model

stating

"A hierarchical database consists of a collection of records that are connected to one another through links. Each record is a collection of fields... The records are organized as a collection of trees."

3. University of Washington

CSE 444: Database Management Systems. (Winter 2015). Lecture 1: Introduction to DBMS. Slide 23. The lecture notes explicitly categorize data models

identifying the Hierarchical Model as a precursor to the Relational Model

characterized by its tree-like structure. Available via UW CSE course archives.

The Internet is fundamentally a packet-switched network. This architecture breaks down data transmissions into small, manageable blocks called packets. Each packet contains a portion of the user data plus control information, including the source and destination IP addresses. These packets are then routed independently across the network and can take different paths to reach the same destination. The receiving device reassembles the packets into the original message. This method allows for efficient sharing of network resources and is a core principle of the Internet Protocol (IP) suite.

A. An IP Alias: This is an optional, secondary IP address for a single network interface and is not required for basic communication.

C. A LAN: A Local Area Network is a common method for connecting to the Internet, but it is not the Internet itself or a universal requirement.

D. A circuit switched network: This model, used by traditional telephone systems, establishes a dedicated circuit for a session, which is fundamentally different from the Internet's packet-switching approach.

E. An analog signal: The Internet's core is digital. While some "last mile" technologies may use analog signaling to transmit digital data, it is not a requirement for the network itself.

1. Kurose

J. F.

& Ross

K. W. (2017). Computer Networking: A Top-Down Approach (7th ed.). Pearson. In Chapter 1

Section 1.3

"The Network Core

" the text explicitly states

"Today’s Internet is a quintessential packet-switched network." It details how data is sent in packets through a network of routers and links.

2. MIT OpenCourseWare. (2012). 6.02 Introduction to EECS II: Digital Communication Systems

Fall 2012. Lecture 15 Notes

"Network Layer: Packet Switching

" page 1. The notes state

"The Internet is a packet-switched datagram network... In a packet switched network

a message from a source to a destination is broken into smaller chunks of data called packets."

3. Cerf

V. G.

& Kahn

R. E. (1974). A Protocol for Packet Network Intercommunication. IEEE Transactions on Communications

22(5)

637–648. This foundational paper for the TCP/IP protocol suite

which governs the Internet

is predicated entirely on the concept of packet switching (referred to as "datagrams") to achieve inter-network communication. (https://doi.org/10.1109/TCOM.1974.1092259)

A computer network is a set of computers sharing resources located on or provided by network nodes. Exhibit A correctly illustrates the fundamental client-server network architecture. In this model, a central, powerful computer (the server) provides information and services to multiple less powerful client computers. This is a basic and widely used structure for organizing computer networks, enabling centralized data storage, management, and resource sharing among connected devices. The other diagrams represent different concepts within information technology.

B. Exhibit B: This diagram depicts a hierarchical structure, such as an organizational chart or a file system directory, not a network of communicating devices.

C. Exhibit C: This is a flowchart, which is used to represent a workflow, process, or algorithm with steps and decision points, not a computer network layout.

D. Exhibit D: This illustrates a relational database schema or an Entity-Relationship Diagram (ERD), showing tables and the relationships between them, not a network structure.

1. Kurose

J. F.

& Ross

K. W. (2017). Computer Networking: A Top-Down Approach (7th ed.). Pearson. In Chapter 2

"Application Layer

" Section 2.1

"Principles of Network Applications

" the client-server architecture is detailed as a primary network model where a central server services requests from multiple clients. Exhibit A is a standard representation of this model.

2. Saltzer

J. H.

& Kaashoek

M. F. (2009). Principles of Computer System Design: An Introduction. Morgan Kaufmann. Chapter 9

"Networking

" Section 9.2.1

"The Client-Server Model" (p. 394)

describes this structure as a common organization for network services.

3. Silberschatz

A.

Korth

H. F.

& Sudarshan

S. (2019). Database System Concepts (7th ed.). McGraw-Hill. Chapter 6

"Database Design and the E-R Model

" explains the use of entity-relationship diagrams

similar to Exhibit D

for modeling the logical structure of databases.

4. Gaddis

T. (2018). Starting Out with Programming Logic and Design (5th ed.). Pearson. Chapter 2

"Input

Processing

and Output

" introduces flowcharts (as seen in Exhibit C) as a tool for programmers to design the logical flow of a program.