A、In an apartment. B、In a bookstore. C、In a classroom. D、In a library. B对话中涉及三个背景词receipt，exchange和book，表明他们应该在书店里。

M：Did you see the diamond ring Henry gave to Mary?
W: I sure did．It must have cost him an arm and a leg．
Q: What does the woman imply about the ring?

W：I need the receipt for the book in order to exchange it．
M：All right．Here you are．
Q：Where does the conversation most likely take place?