听力原文：W: Gosh! Kevin, are you OK？ Another cup of coffee？M: Yeah, I stayed up all night

听力原文：W: Gosh! Kevin, are you OK？ Another cup of coffee？

M: Yeah, I stayed up all night cramming for my poetry exam. I couldn't keep my eyes open in my last class. I'm having this coffee so I can stay awake this afternoon.

W: Haven't you ever heard that drinking too much coffee is harmful to your health？

M: It's a little odd. What do you mean harmful？

W: Well, for one thing it may cause heart disease.

M: Most of the research about the link between coffee and heart disease is inconclusive.

W: But coffee has caffeine that is addictive, once addicted, it's hard to kick it off.

M: Not so horrible. You can't become addicted to caffeine like other drugs.

W: Yes, you can. Don't you know that people who are deprived of caffeine suffer with draw symptoms, especially headache？

M: Oddly enough, one cure for headache is caffeine. Besides, coffee helps me work faster？

W: Studies have showed that coffee makes you work faster but not necessarily better. You may finish your exam in a shorter period but you won't have fewer errors.

M: You know, soda in your drink has caffeine too.

W: But 12 ounces of soda has half the caffeine of a 5 ounces cup of coffee. And a cup of tea has less than that.

M: But I cannot resist the taste of coffee.

W: You could drink decal Decaffeinated coffee doesn't have as much flavor or body as regular coffee.

What is the conversation mainly about？

A．How to do well on poetry examination.

B．The effect of caffeine.

C．Some causes of heart disease.

D．Problems with the man's cafeteria.