it is 8086 question AX(16 bit) =AH( 8 bit) +AL (8 bit)
MOV AL ,15 // 00001111 in AL
mov ah, 15 // 00001111 in AH and AX =0000 1111 0000 1111
xor al, al // AL is 0000 0000 now and so AX =0000 1111 0000 0000
mov cl, 3 // CL is 0000 0011
shr ax, cl //AX = 000 0000 1111 0000 0 or (01E0) h
add al, 90H // AL= 1001 0000 add this to( AX=AH+AL) , now AX =0170 h with carry 1
adc ah, 0 // add 0 to ah with carry which is one so final ans 0270 h
so ans is A