A、A doctor. B、A reporter. C、A scientist. D、A professor. A讲话者讨论的是医学问题，所以可能是医生。

I don’t think there is anything wrong with your blood. The key to your problem is that long sleep after dinner.
    If you didn’t sleep for hours during the early part of the evening, you would be more ready to sleep at bedtime, If you didn’t nap after dinner, you would not want to stay up so late, and you would not feel the need to take a sleeping pill. The pill is still working in your system when you get up in the morning. This helps account for the fact that you feel tired all day.   
    You should get out of the habit of sleeping during the evening. Right after your evening meal, engage in some sort of physical activity--a sport such as bowling, perhaps. Or get together with friends for an evening of cards and conversation. Then go to bed at your usual time or a little earlier, and you should be able to get a good night’s rest without taking a pill.
    If you can get into the habit of spending your evenings this way, I am sure you will feel less fired during the day. At first it may be hard for you to go to sleep without taking a pill. If so, get up and watch television or do some jobs around your house until you feel sleepy. If you fall asleep and then wake up a few hours later, get up but do not take a sleeping pill. Read a while or listen to the radio, and get yourself a few hours’ sleep that night, you will feel better in the morning than you usually feel after taking a pill. The next night you will be ready to sleep at an earlier hour.
    The most important thing is to avoid taking that sleep right after dinner and avoid taking pills.