Which of the following is TRUE of the service at a

单项选择题

Questions 1 to 5 are based on an interview. At the end of the interview you will be given 10 seconds to answer each of the following five questions.
Now listen to the interview.

Which of the following is TRUE of the service at a bar

A．A customer has to tip the waitress.
B．A customer has to pay each time he gets drinks.
C．A customer has to pay for all the drinks when he is leaving.
D．A customer has to sit at the table to wait for their turn to be serve