W: I'm sending a letter to my friend by airmail. It's not insured or anything, but how do I address it, again? M: Well, obviously you have to write the name of the person or business in the center of the envelope. W: Okay. What next? M: On the second line, you write the address you are sending it to. Good, like that. W: I got it now. On the last line, I write the city it's going to and the district, right? M: Don't forget to write the return address in the upper - left corner in the same manner as the sending address. W: Now I just need to get a proper postage stamp., Question: What does the woman still need to buy? (A) A postage stamp. (B) A proper envelope. (C) Airmail insurance.
(A) A postage stamp.