问题详情

Speaker A: Thank you very much for helping me with my history. Speaker B: ______

A．Sure thing. Don"t thank me!

B．You"re welcome. I"m glad I can be of help.

C．It was a piece of cake! Don"t mention it!

D．Oh, this is what I should do.

请帮忙给出正确答案和分析，谢谢！