单选题 Man: I'm exhausted. I stayed up the whole night studying for my midterm math exam.
Woman: But why do you always wait until the last minute?
Question: What does the woman imply?
A. The man is usually the last to hand in his test paper.
B. The man has made a mess of his midterm exam.
C. The man has bad study habits.
D. The man is a diligent student.