The content of top of a memory stack is 5320. The content of stack pointer SP is 3560. A two-word call subroutine instruction is situated in the memory at address 1120 followed by the address field of 6720 at location 1121. State the content of PC, SP, and the top of the stack in the following situations:
a) Before call instruction is fetched from memory.
b) After the call instruction is executed.
c) After return from the subroutine.