A、In place of physical therapy. B、To control brain problems. C、To prevent heart disease. D、To relieve depression. DAccording to

M: Good evening, dear audience. I’m glad to continue the topic about music. It is common knowledge that music can have a powerful effect on our emotion. In fact, since 1930s, music therapists have relied on music to soothe patients and help control pain. Now psychologists are confirming that music can also help relieve depression and improve concentration.
W: That’s nice. Do they have any concrete examples?
M: For instance, in a recent study, 15 surgeons were given some highly stressed math problems to solve. They were divided into three groups: one worked in silence; and in another, the surgeons listened to music of their choice on headphones; the third listened to classic music chosen by the researchers.
W: What’re the results?
M: The results of the study may surprise you. The doctors who got to choose their music experienced less stress and scored better than the others.
W: That is surprising. How to explain this?
M: One possible explanation is that listening to music you tike stimulates the Alfa-wave in the brain, increases the heart rate and expands the breathing. That helps to reduce stress and sharpen concentration.
W: Is there any other research?
M: Yes. Other research suggests a second relation between the music and the brain; by examining the student’s blood after listening to a variety of classical music collections, the researchers found that some students showed a large increase in a chemical substance, a natural pain reliever, in their blood, which can held soothe the patient.
W: Well, thank you so much for being with us today and having us know about another function of music.