Which statement best captures a difference in service models regarding control over hardware and software?

• A. IaaS provides the most control over hardware; PaaS provides a platform for deploying apps; SaaS delivers software over the Internet.
• B. PaaS provides the most control over hardware; IaaS provides platforms; SaaS provides software
• C. SaaS provides the most control over hardware; IaaS provides software; PaaS provides platforms
• D. CaaS provides the most control over hardware; IaaS provides software; PaaS provides platforms

Answer: (A)

The question tests how much control you have over hardware and software across cloud service models. In IaaS you get virtualized hardware resources and a lot of control: you choose and manage the operating system, middleware, runtime, and applications, while the provider handles the physical hardware and virtualization. In PaaS you’re given a platform with a managed runtime and tools to deploy and run your apps; you focus on the code and configuration, while the provider takes care of the underlying OS, middleware, and infrastructure. In SaaS you’re using software that’s fully managed by the provider over the Internet; you don’t manage the hardware, OS, or the software stack at all.

So the statement that best captures this progression is the one that says IaaS provides the most control over hardware, PaaS provides a platform for deploying apps, and SaaS delivers software over the Internet. The other options mix up who controls what—for example, suggesting PaaS has the most hardware control or that IaaS provides platforms—so they don’t fit how responsibilities change across service models.