TOEFL Listening: TPO-TOEFL听力TPO - FC8NPH5JGN81QPE8R$

What opinion does the professor express when she says this: A. That the topic is too controversial to be the focus of the man's paper B. That too many papers have already been written on the topic C. That the topic does not seem to meet the requirements of the assignment D. That there has not yet been any research published on the topic