The free command reports slightly less memory than the actual total memory available. Why is it
so?
A.
The swap space occupies a portion of the main memory that can never be freed.
B.
The multiple instances of a program like shell, being run, consumes a portion of the main
memory that cannot be freed.
C.
The kernel remains in the main memory while the computer is in operation and the memory it
occupies can never be freed.
D.
The zombie processes that exist in the process table occupy a slightly less portion of the main
memory that can only be freed on reboot.
Explanation: