— I really don’t know how to thank you enough— . A. No problemB. Think nothing of itC.

— I really don’t know how to thank you enough.
— .
A. No problem
B. Think nothing of it
C. Not at all
D. It doesn’t matter

A. No problem(答案→)B. Think nothing of itC. Not at allD. It doesn’t matter解析：考查交际用语：A. No problem没问题B. Think nothing of it没什么大不了的（回答对方的感谢）C. Not at all一点也不 D. It doesn’t matter没关系，句意：--我真不知道怎么感谢你。--没什么。选B。

谢谢了