TOEFL Listening: ETS-TOEFL听力机经 - H28AIUV80209YF10P$

Why does the student say this: A. She is disappointed ha the students in the library would not like the group's presence. B. She does not understand the professor's point clearly. C. She wants to discover a way to make observations in secret. D. She thinks that the observations they have made so far have not affected the student behavior.