Anne's father,as well as her mother, --- in New York for a f

Anne's father,as well as her mother, ___ in New York for a few more days.A ask him to stay B ask he to stay c asks he stays D ask he stay 我选的是c,答案是d. he 不会单数吗?而且ask 不是ask sb to do sth 吗?D 选项我打错了。是asks he stay 。其它的就没错了。还有是我想问那个"he"为什么不影响stay这个从句中的谓语形式。为什么是stay而不是stays.印刷没问题。最新……………………我自己想了一下，会不会是因为是ask表示要求。stay其实是should stay 虚拟语气呢？？？