In secure computing systems, why is there a logical form of separation used between processes?

A.
Processes are contained within their own security domains so each does not make unauthorized accesses to other processes or their resources.

B.
Processes are contained within their own security perimeter so they can only access protection levels above them.

C.
Processes are contained within their own security perimeter so they can only access protection levels equal to them.

D.
The separation is hardware and not logical in nature.

Explanation:
A: Processes are assigned their own variables, system resources, and memory segments, which make up their domain. This is done so they do not corrupt each others data or processing activities.