——I think it's a good idea.——___________ A.i think so B.i'm afraid so.C.i don't think so.

问题描述:

——I think it's a good idea.——___________ A.i think so B.i'm afraid so.C.i don't think so.
为什么答案是C,AB都不行吗?

A 可以是I also think so
B i'm afraid not