TOEFL Listening: TPO-TOEFL听力TPO - X8Y70V17EJ2M20N4R$

Why does the professor say this: A. He does not understand why the student is talking about engineers. B. He wants to know how the engineers will communicate with their coworkers. C. The student has not provided a complete answer to his question. D. He wants the student to do more research on the topic.