Which is the layer of a computer system between the hardware and the user program?

1. Operating environment
2. Operating system
3. System environment
4. None

Which of the following is NOT a function of an operating system ?

1. Managing the computer's resources, such as the central processing unit, memory, disk drives, and printers.
2. Formatting a word document.
3. Establishing a user interface.
4. Executing and providing services for applications software.

Which is not the function of an operating system ?

1. Memory management
2. Disk management
3. Application program management
4. Virus protection

In which of the following OS types, the response type is very crucial ?

1. Unix operating system
2. Real Time OS
3. Time sharing OS
4. Single user OS