Concept:The central role of system software is to supervise and control the computer's hardware and software operations.
Explanation:System software, commonly known as the operating system, manages the computer's internal operations.
It controls the central processing unit, memory, input/output devices, and other peripherals such as the monitor, printer, and storage devices.
It also coordinates the running of application programs and directs system resources to where they are needed, guaranteeing smooth functioning.
Helping the user navigate easily is a duty of the user interface, while utilities and maintenance tools give additional support.
These are necessary assistance functions but not the primary major role of system software.
Therefore, the major function of system software is to control and supervise the whole computer system.
Answer:C. Controlling the computer system.