Which of the following is not an operating-system service?

Concept: An operating system manages hardware resources and provides a controlled environment in which programs execute.

Its standard services include input/output handling, protection, resource allocation, and usage accounting. Language translation is performed by system programs such as compilers.

Application: Protection controls access to shared resources; accounting records their use; and I/O handling coordinates program requests with devices. Compilation instead translates source code through a compiler.

• Protection concerns access control for memory, files, and devices.

• Accounting concerns measurement and recording of resource use.

• Compilation concerns translating source code into target or executable code.

• I/O operation handling concerns communication between programs and devices.

Cross-check: Classifying each value by its responsible component separates operating-system resource services from language-processing work.

Result: Compilation is not an operating-system service among the offered choices.