---It’s very nice of you to help me solve such a big problem.---.A. That’s all right.B. Do

问题补充：

---It’s very nice of you to help me solve such a big problem.

---.

A. That’s all right.

B. Don’t worry.

C. It’s my pleasure.

D. Take it easy.

答案：

A. That’s all right.

B. Don’t worry.

(答案→)C. It’s my pleasure.

D. Take it easy.

解析：情景交际. That’s all right.没关系; Don’t worry.不要担心;It’s my pleasure.这是我的荣幸; Take it easy.放松点.根据上文,帮我解决如此一个大的难题,你真是太好了.结合语境可知选C,