Given the task definition and input, reply with output. In this task you are given a small conversation between two persons and 4 options on how the conversation should continue. Your job is to choose the most reasonable option. The conversation and the options are separated by a newline character. Each dialogue in the conversation are separated by a comma. F and M indicate female and male, respectively.

M: I'd like this letter to go by EMS. What's the rate? ,F: $7.65 for up to 2 pounds. ,M: Thank you. I hear the EMS is the next day service. Is that true? ,F: Well, it's true within America, but now you are in Beijing. The letter has to go through customs and get registered there. Anyway, it's faster and safer than ordinary mail.
(A) M: I know it is cheaper than ordinary mail, but I need to check the rate first since you don't know it. (B) M: I know it is faster and safer than ordinary mail, so I would like to send my letter through EMS. (C) M: I am really sorry, I did not catch that. Would you slow down, please? (D) M: Yes, EMS is faster and safer than ordinary mail, but it is not the next day service within America.
B