John ,you need not do your work today,you--do it tomorrow if you are tired.a,must b may c can not

题目

John ,you need not do your work today,you--do it tomorrow if you are tired.a,must b may c can not
i am sorry i did not win the game .-well,that is ok,you ---win every time.A must not B can not C should not D may not
请说明原因谢谢
D 为什么?有两个问题,

答案

选B、can not
A、must not：禁止
B、can not:
C、should not:不应该
D、may not:可能不
按意思应选B