F: This book originally cost $30, but I got a 20% discount. Unfortunately, I've only got $15. ,M: I've got $13.00, so I'll lend you the rest.
(A) F: I am afraid I did not quite catch what you were saying. Please repeat it. (B) F: Thank! The book is 50% off, I just have $15. (C) F: Thanks! Then I pay $24 for the CD. (D) F: Thanks! Can you lend me $9 so I can pay $24 in total.
D