根据对话内容，从方框中选出适当的选项补全对话。

A: Hi, Jenny. Where is my pen?

B:  Is it on your desk?

A: No, it isn't.

B: Oh! It's under the teacher's desk.

A:

B: You're welcome. Oh, I find a ruler here, too.  

A: No. I think it is Jack's.  

B:

A: OK.

A. Is it yours? B. I don't know. C. Thank you for your help. D. Well, I'll ask Jack about it. E. And it's not under my chair.