Which of the following is not a service supported by an operating system?

Concept

An operating system manages hardware resources and provides standard services that programs and users need, such as controlled input/output, resource accounting, and protection. A compiler is a language-processing tool: it translates source code into another form.

Application

Compare each choice with the standard operating-system service categories. Protection, accounting, and I/O operations are listed OS responsibilities. Compilation belongs to the program-development toolchain, so Compilation is the service not supported as an operating-system service in this classification.

Contrast and cross-check

• Protection controls access to processes, memory, files, and devices.

• Accounting records how users and processes consume resources.

• Compilation translates source programs into object or executable code.

• I/O operations provide controlled data transfer between programs and devices.

Result

Therefore, the required value is Compilation.