If a station officer finds that there is a passenger standing before a ticket gate who can’t get in for some reasons, what should he or she do?

A、A station officer should go up and check what’s going wrong.;
B、A station officer should advise the passenger to go to the customer card service center to process his card if an error code appears on the ticket gate screen.;
C、A station officer should advise the passenger to top up his card in the customer card service center if the passenger’s card balance is insufficient.;
D、A station officer should advise the passenger to go to another ticket gate to get in if he or she confirms that there is something wrong with the current ticket gate.