which state must a computer system operate to process input/output instructions?

In which state must a computer system operate to process input/output instructions?

A.
User mode

B.
Stateful inspection

C.
Interprocess communication

D.
Supervisor mode

Explanation:
A computer is in a supervisory state when it is executing these privileged
instructions. (privileged instructions are executed by the system administrator or by an individual
who is authorized to use those instructions.) . -Ronald Krutz The CISSP PREP Guide (gold
edition) pg 254-255