【正确答案】 A

【答案解析】[听力原文]
   W: Hello, I'm Jenny Johnson. How are you this morning?
   M: Hello! Doctor Johnson, I can't say I'm feeling well. I have a pain and swelling in my knees.
   W: What kind of pain is it?
   M: It is a dull ache. But sometimes the pain is constant, and disturbs my sleep.
   W: How long have you been feeling pain in your knees?
   M: For about two years. But recently, I feel pain in my fingers.
   W: Have you had any swelling in your fingers?
   M: Yes, a little.
   W: How about your wrists or toes?
   M: No, only my knees and fingers. The pain becomes worse when the weather changes, like in cloudy or wet weather.
   W: OK. Let me see your blood test report first.
   M: How is it?
   W: Not very bad.
   M: Do I have to have an operation?
   W: No, I don't think so. I'll prescribe some traditional Chinese medicine. Also you need a treatment with rays below the red in the spectrum.
   M: Do I have to come here every day for the treatment?
   W: Not every day. Can you come three times a week? A course of treatment includes 20 times, so you have to come for the treatment three times a week for seven weeks.
   M: How long does each treatment take?
   W: 30 minutes.
   M: OK. I'll do that.
   W: When you are at home, use these hot water pads as often as possible. Put one over your knees. Try to avoid using cold water.
   M: OK. Thank you, Doctor.
   W: You're welcome.
   What is the problem with the man?