Correct Option: D

The following sequence of micro-operations
MBR       ← PC
MAR     ← X
PC ←     Y
Memory     ← MBR.
Analysis
1. First micro operation stores the value of PC into Memory Base Register (MBR).
2. Second micro operation stores the value of X into Memory Address Resister (MAR).
3. Third micro operation stores value of Y into PC.
4. Fourth micro operation stores value of MBR to memory.
So before execution of these instructions PC holds the value of next instruction to be executed. We first stores the value of PC to MBR and then through MBR to memory i.e., We are saving the value of PC in memory and then load PC with a new value. This can be done only in two types. Operations Conditional branch and interrupt service.
As we are not checking here for any conditions. So, it is an Initiation of interrupt service.