—Would you like me to help you with the maths problem?— It’s a most difficult one.A. With

问题补充：

—Would you like me to help you with the maths problem?

— It’s a most difficult one.

A. With pleasure.

B. Why not?

C. That’s all right.

D. It’s my pleasure.

答案：

A. With pleasure.

(答案→)B. Why not?

C. That’s all right.

D. It’s my pleasure.

解析：考查交际用语：A.With pleasure.很乐意，B.Why not?好啊， C.That’s all right.没关系，D.It’s my pleasure.不用谢，句意：--你想要我帮助你做这个数学题吗？--好啊，这是最难的一题。选B。