"have his head in the clouds”的意思?

问题描述:

"have his head in the clouds”的意思?
如题,只需写出答案
"A good student should have his head in the clouds sometimes,but
his feet are always on the ground.”
A.头顶云雾 B.抓住机会 C.富于幻想 D.勇攀高峰

C.富于幻想