TOEFL Listening: ETS-TOEFL听力机经 - UQ6YVLC13DT6L8V3P$

Why does the man go to see his professor? A. He wants to change his paper topic. B. He doesn't understand how to analyze bird migration. C. He cannot find enough information on his term paper topic. D. He doesn't understand the ideas that he has been reading about.