单项选择题

Questions 17 to 20 are based on the following passage. At the end of the passage, you will be given 20 seconds to answer the questions.
Now, listen to the passage.
When does the library close on Friday nights

A.8:30 p.m.
B.9:00 p.m.
C.9:30 p.m.
D.10:00 p.m.