20. Passenger 1: Excuse me. I think this is my seat.Passenger 2: Really? But my seat is 33.Passenger 1: Mine is 33, too. Look at my ticket.Passenger 2: Oh, _______________ But you’ve just missed it!
(A) your train hasn’t come yet.
(B) you need to get on the train.
(C) your ticket is for an earlier train.
(D) you should change your ticket.