听力原文：W: Do you think a hobby is important to a college student？
M: Sure. I think it can help improve the quality of life.
W: You are right. Hobbies are necessary for a person's happiness.
M: But very often, college students are too busy to have hobbies.
W: So first you should know how to arrange your time.
M: Yes. By the way, do you have any hobby？
W: Well, my hobby is learning English.
M: Do you call that a hobby？ That's the thing you have to do at college.
W: Of course. But I really take it as a fun. I read novels.
M: Oh, to me, learning English is not so easy.
(16)

A. Habits.
B. Happiness.
C. Lessons.
D. Hobbies.