单项选择题

Questions 1 to 3 are based on the following conversation. At the end of the conversation, you will be given 15 seconds to answer the questions. Now, listen to the conversation.
Why does the student say that it’s complicated and embarrassing

A.To confess that he lied to the professor.
B.To emphasize what he is about to say.
C.To prove that he is innocent.
D.To warn the professor not to ignore him.