单项选择题

W: Richard works as hard as his roommate.
M: That’s not saying very much.
W: Do you mean that he does not have a good performance at school
M: I don’t really mean that.

What conclusion can be drawn from this conversation()

A. Richard is hard to work.
B. Richard speaks with difficulty.
C. Richard’s does not necessarily bring satisfactory results.
D. Richard doesn’t work very hard.