A.MOV AX,BX B.MOV AX,[BX] C.MOV AX,CX D.MOV AX,[CX]
A.AND AL,0FH B.AND AL,0FOH C.OR AL,0FH D.OR AL,0FOH
A.-2n<x<2n B.-2n≤x≤2n-1 C.-2n-1≤x≤2n-1 D.-2n<x≤2n