value 7 is placed in register pair B
every time value is reduced by one by DCX B
contens of B are moved to Accumaulator
and logical OR is performed with C
but that do dont affect the repetion of loop which is controlled by JNZ (jump is not zero) LOP instruction so loop executes for B values 7,6,5,4,3,2,1 total 7 times
Hence ans is B