Is John coming by train? he should ,but he ___not.he likes diving his car.A,must B,can C,may D,should 并加上理由,谢谢

Is John coming by train? he should ,but he ___not.he likes diving his car.A,must B,can C,may D,should 并加上理由,谢谢
Is John coming by train? he should ,but he ___not.he likes diving his car.
A,must      B,can     C,may    D,should                            并加上理由,谢谢

Is John coming by train? he should ,but he ___not.he likes diving his car.A,must B,can C,may D,should 并加上理由,谢谢
may

he should翻译为“按道理是这样的”，但是。。。；通过转折可以知道作者是不太确定的，四个选项里面may的推测最不确定。must表示推测，只能用于肯定句，can't表示推测，翻译成“一定不”；shouldn't 没有表示“推测”的用法。