I can't remember his mobile phone number.What___I do?A.can B.could C.may D.should

问题描述:

I can't remember his mobile phone number.What___I do?A.can B.could C.may D.should
为什么选D不选A呢?

我记不起来他的电话了,选择A是我可以怎么做?选D是我应该怎么做呢?should带有虚拟语气,表示委婉的应该怎么做,寻求帮助.