Which statement about an operating system is NOT true?

• A. It is a set of programs that coordinate all activities of hardware resources.
• B. It is the layer between the application software and the hardware.
• C. It is unique to each individual computer hardware system.
• D. There is only one operating system available for all computers.

Answer: (D)

An operating system coordinates how hardware resources are used and provides a stable platform for applications to run. It manages CPU time, memory, storage, and I/O devices, offering services and a consistent interface so software doesn’t need to know the specifics of the hardware. It sits between application software and the physical machine, handling de facto safety, efficiency, and compatibility.

The statement about there being only one operating system for all computers isn’t correct because there are many OS options designed for different hardware designs and use cases. Windows, macOS, Linux, Android, iOS, and various embedded or real-time operating systems all exist to suit different architectures and needs. Some devices indeed run a specific OS, but others can run multiple OS choices or switch between them, and virtualization can let one machine host several OSes. This variety is what makes the single-OS claim inaccurate.