The scenario requires a cloud service model that provides base-level computing resources (servers, storage, networking) without the need to purchase physical hardware, while granting the company complete control over the operating system (OS) and software. Infrastructure as a Service (IaaS) is the only model that meets these criteria. IaaS offers virtualized infrastructure components, allowing the customer to deploy and run their own software, including the OS and applications. The cloud provider manages the underlying physical hardware, but the customer retains control over the virtualized environment, including the OS.

A. Software as a Service (SaaS) provides ready-to-use applications, offering no control over the underlying OS or infrastructure.

B. Function as a Service (FaaS) is a serverless model where the provider manages the OS, abstracting it entirely from the user.

D. Platform as a Service (PaaS) provides a development platform where the provider manages the OS, limiting user control to applications.

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1. Mell

P.

& Grance

T. (2011). The NIST Definition of Cloud Computing (Special Publication 800-145). National Institute of Standards and Technology.

Page 2

Section "Infrastructure as a Service (IaaS)": "The capability provided to the consumer is to provision processing

storage

networks

and other fundamental computing resources where the consumer is able to deploy and run arbitrary software

which can include operating systems and applications. The consumer does not manage or control the underlying cloud infrastructure but has control over operating systems

storage

and deployed applications..." This directly supports the choice of IaaS for control over the OS.

2. Microsoft Azure Documentation. (n.d.). What is IaaS?

Section "What is IaaS?": "The cloud computing service provider manages the infrastructure

while you purchase

install

configure

and manage your own software—operating systems

middleware

and applications." This official vendor documentation confirms that in the IaaS model

the customer manages the operating system.

3. 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 3

Section 3.1 "Levels of Virtualization": The report describes Infrastructure-as-a-Service (IaaS) as a model where the cloud provider offers virtual machines (VMs). It states

"A user of IaaS can run any software they can run on a physical machine

including an operating system and applications." This academic source validates that IaaS provides the required level of control over the OS.