(b) The requirement is to identify the most common
type of primary storage in a computer. Answer (b) is correct
because RAM (Random Access Memory) is the most common
computer memory which can be used by programs to perform
necessary tasks; RAM allows information to be stored or accessed
in any order and all storage locations are equally accessible.
Answer (a) is incorrect because CMAN has no meaning in
information technology. Answer (c) is incorrect because ROM
(Read Only Memory) is memory whose contents can be accessed
and read but cannot be changed. Answer (d) is incorrect
because it is a nonvolatile storage that can be electrically erased
and programmed anew that is less common than RAM.