单项选择题

Questions 15-18 are based on the following conversation. You now have 20 seconds to read the questions 15-18. Why couldn’t the passenger use the train ticket to pay for the bus ticket

A.The train ticket costs more than the bus ticket.
B.The train station belongs to another company.
C.Her uncle and aunt don’t agree with him to do so.
D.She doesn’t want to pay extra money to the bus station.