When a passenger cannot get out of the station, what should a station officer do?
A.
A station officer should approach him and inquire him that if he has already bought a ticket.
B.
A station officer should ask the passenger to buy a new ticket if he cannot find his ticket.
C.
A station officer should explain the subway company regulation to the passenger.
D.
A station officer should remind the passenger to take care of his ticket next trip.