— go to the Great Wall this Sunday?—I’m afraid it is not a good idea. Many of us have been

— go to the Great Wall this Sunday?
—I’m afraid it is not a good idea. Many of us have been there.
A. Why not
B. What about
C. Would you like
D. You’d better

(答案→)A. Why notB. What aboutC. Would you likeD. You’d better解析：Why not为何不……；What about……怎么样，后面接名词或者动名词； Would you like你想不想，后面一般接名词或者不定式；You’d better你最好……，为肯定语气。根据后面动词go及语境可知选A。

哦，回答的不错