A、Worry. B、Happiness. C、Emotion. D、Anger. B原文中提到，相比之下，一个人从年轻到年老，快乐和幸福等正面情绪改变很小。因此答案为B。

Movies often depict the elderly as ill-tempered. In fact, most elder people have fewer negative feelings, like anger, than the young.
    Recent research into how emotions change with age may be able to help people lead healthier and longer lives and bring about new treatments for depression in the elderly.
    Like people’s bodies, emotions change over time. Older people for the most part have far fewer negative feelings, such as worry and stress, than younger people do, studies show.
    The elderly learn to free themselves from feelings of negativity and seem to focus more on present situations that bring pleasure, rather than on the future, researchers say. They also tend to process negative information less deeply than positive information.
    By contrast, positive feelings such as enjoyment and happiness change very little from the time when a person is in his youth until old age.
    "It seems to be essential for our emotional well-being to not look back in anger and to focus on the positive when we are older, " Stefanie Brassen, a researcher at the University Medical Centre Hamburg -Eppendorf, said in an email.
    Older people who are depressed seem not to use the sort of emotional regulation typically seen in the elderly, researchers say. Depression affects some 6 million Americans over the age of 65, or about 15％ of the total, and is believed to be a big reason why the elderly have the highest suicide rate, according to the non-profit Geriatric Mental Health Foundation.
    In a potential new treatment approach, Dr. Brassen and his colleagues are developing a training program in which older people practice strategies to better adapt to life circumstances.
    Questions 9 to 12 are based on the passage you have just heard.
    9. How do movies depict the old?
    10. According to the researchers, what do the old pay more attention to?
    11. What changes less over time as a person is getting old?
    12. What is an important factor contributing to the highest suicide rate in the American elderly?