M: How much is the cap? ,F: 8 yuan for 1, 14 yuan for 2, and 18 yuan for 3. ,M: Then I'll take 3.
(A) F: 8 yuan, please. (B) F: OK. These four caps cost 18 yuan. (C) F: 14 yuan, please. (D) F: I am afraid I did not quite catch what you were saying. Please repeat it.
D