单项选择题

有8086/8088的汇编指令:MOV AX,4567H CWD,以上两条指令执行完成后DX,AX的值为()

A.DX=0AX=4567H
B.DX=0FFFFH AX=4567H
C.DX=0AX=FF67H
D.DX=0XFFFFH AX=FF67H