TOEFL Listening: ETS-TOEFL听力机经 - GW5C575YKG7U84D4P$

What does the professor imply about the student's extended field trip? A. He would like to know more about the fieldwork the student did. B. He was unaware of the problems the student had on the trip. C. He knew that there would be problems on the trip. D. He has been in similar situations himself.