A.-25 B.25 C.24 D.25H
A.XCHG AX,DI B.XCHG BX,[SI+3] C.XCHG AL,20H D.XCHG NUM,DX
A.MOV AX,1234H B.MOV BX,[1234H] C.MOV DS,AX D.MOV 2000H,AX