The operating system of a computer is responsible for managing which of the following?

Introduction / Context:
The operating system (OS) is the fundamental system software that sits between computer hardware and application programs. It manages hardware resources and provides a platform on which applications can run. Understanding the broad responsibilities of an operating system is an important part of basic computer literacy.

Given Data / Assumptions:

• The options mention CPU management, services for applications, and user interface.
• We are asked which areas the operating system manages.
• We assume a general purpose operating system like Windows, Linux, or macOS.
• The OS is viewed as the main controller of hardware resources and user interaction.

Concept / Approach:
An operating system performs many tasks. It schedules CPU time among processes, controls which process runs at any moment, and handles context switching. It offers system calls, libraries, and services so that application software does not need to directly manage hardware. It also provides a user interface, either graphical or command line, to interact with the system. Since all three functions listed are part of the OS responsibilities, the correct answer is All of the above.

Step-by-Step Solution:
Step 1: Consider CPU management: the OS decides which process runs, for how long, and manages multitasking.Step 2: Consider services for applications: the OS provides file handling, memory management, device access, and networking through APIs.Step 3: Consider the user interface: the OS provides windows, icons, menus, or command line shells for user interaction.Step 4: Recognize that all three roles are central and widely documented duties of an operating system.Step 5: Choose All of the above as the answer that best describes the scope of OS management.

Verification / Alternative check:
Standard operating systems textbooks define the OS as responsible for resource management, program execution, and user interface handling. The kernel manages CPU and memory, the system services support applications, and user space components such as window managers handle the user interface. This confirms that each item in the options is indeed an operating system responsibility.

Why Other Options Are Wrong:
Picking only CPU management would ignore the critical role of the OS in providing services to applications. Selecting only services or only user interface would miss the resource management purpose. The combined option All of the above correctly reflects the complete set of responsibilities and is therefore the only fully accurate choice.

Common Pitfalls:
Some learners focus only on the visual part of the operating system and think that its main role is the user interface. Others focus only on technical aspects like CPU scheduling. In reality, the OS must coordinate hardware, provide abstractions for applications, and support user interaction at the same time. Keeping this broader view helps in understanding later topics such as process management and file systems.

Final Answer:
The correct answer is All of the above, because an operating system manages the CPU, provides services for application software, and establishes and controls the user interface.