【单选题】

In this section you will hear several conversations. Listen to the conversations carefully and then answer the questions that follow.

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 woman go to see the professorA．To find out if he is teachingChemistry 221.
B．To find out if she can take a class.
C．To find out the prerequisites for his class.
D．To find out how many students are in the class.