单项选择题

Questions 5 to 7 are based on the following conversation. At the end of the conversation, you will be given 15 seconds4 to answer the questions.
Now listen to the conversation.

Why is Helen buying the tickets

A.She gets a student discount.
B.Bob doesn’t have very much money.
C.She lost a bet and owes Bob money.
D.Bob left his wallet at hom