TOEFL Listening: TPO-TOEFL听力TPO - 44MYV3JPKG507OT4R$

Why does the professor say this: A. To indicate that he understands why the student may be confused B. To emphasize that the student has asked a very important question C. To remind the student that she may know the answer to her own question D. To invite other members of the class to answer the question