Operating System (OS)
The Memory Address Register

is a group of electrical circuits (hardware), that performs the intent of instructions fetched from memory.
contains a copy of the designated memory location specified by the MAR after a "read" or the new contents of the memory prior to a "write".
contains the address of the memory location that is to be read from or stored into.
None of these
is a hardware memory device which denotes the location of the current instruction being executed.

ANSWER DOWNLOAD EXAMIANS APP

Operating System (OS)
Memory management is :

not used on multiprogramming systems
not used in modern operating system
critical for even the simplest operating systems
None of these
replaced with virtual memory on current systems

ANSWER DOWNLOAD EXAMIANS APP