单项选择题

Questions 4 to 7 are based on the following conversation. At the end of the conversation, you will be given 20 seconds to answer the questions.
Now listen to the conversation.

What does a student usually have to do before taking the advanced sketching course

A.Write a book.
B.Attend an afternoon meeting.
C.Enroll in another class.
D.Go to the art museum.