选择合适的句子，补全对话。

Mary: Excuse me.

Tom:

Mary: I want to buy a bag online.

Tom:

Mary: How much is it?

Tom:

Mary:

Tom: Okay!

A. It's 100 yuan.

B. I'll take it.

C. Can you help me?

D. Sure. Look! Here it is.

E. Yes? What can I do for you?