M: Mary, do you sit next to Sandra in the classroom? ,F: No, I sit in the back row. She used to sit by the window, but now she sits by the door.
(A) M: Don't sit by the window. Sandra sits by the window now. (B) M: That's a good idea to sit by the door. Sandra also used to sit by the door. (C) M: I didn’t hear you. Please could you tell me again? (D) M: Okay. So you sit next to Sandra, and just sit in the back row.
C