Are people less happy or more happy the older they get ? A study found that people generally become happier and experience less worry after age 50. In fact, it found that by the age of 85, people are happier with their life than they were at 18. The finding came from a Gallup survey of more than 340,000 adults in the United States in 2008. At that time, the people were between the age of 18 an 85. Arthur Stone in the Department of Psychiatry and Behavioral Science at Stony Brook University in New York led the study. His team found that levels of stress were highest among adults between the ages of 22 and 25. Stress levels dropped sharply after people reached their fifties. Happiness was highest among the youngest adults and those in their early seventies. But the people least likely to report feeling negative emotions  were those in their seventies and eighties. The survey also found that men and women had similar emotional patterns as they grow older. However, women at all ages reported more sadness, stress and worry than men did. The researchers also considered possible influences like having young children, being unemployed or being single. But they found that influences like these did not affect the levels of happiness and well-being related to age. So why would happiness increase with age ? One theory is that, as people get older, they become more thankful for what they have and have better control of their emotions. They also spend less time thinking about bad experiences. The original  goal of the study was to confirm the popular belief that aging is connected with increased sleep problems. The survey did find an increase during middle age, especially in women. But except for that , people reported that they felt their sleep quality improved as they got older. Old people may be happier probably because   _
their children have grown up. they don't have to work every day. they can do whatever they like best. they are most likely satisfied with life.
Question: Are people less happy or more happy the older they get ? A study found that people generally become happier and experience less worry after age 50. In fact, it found that by the age of 85, people are happier with their life than they were at 18. The finding came from a Gallup survey of more than 340,000 adults in the United States in 2008. At that time, the people were between the age of 18 an 85. Arthur Stone in the Department of Psychiatry and Behavioral Science at Stony Brook University in New York led the study. His team found that levels of stress were highest among adults between the ages of 22 and 25. Stress levels dropped sharply after people reached their fifties. Happiness was highest among the youngest adults and those in their early seventies. But the people least likely to report feeling negative emotions  were those in their seventies and eighties. The survey also found that men and women had similar emotional patterns as they grow older. However, women at all ages reported more sadness, stress and worry than men did. The researchers also considered possible influences like having young children, being unemployed or being single. But they found that influences like these did not affect the levels of happiness and well-being related to age. So why would happiness increase with age ? One theory is that, as people get older, they become more thankful for what they have and have better control of their emotions. They also spend less time thinking about bad experiences. The original  goal of the study was to confirm the popular belief that aging is connected with increased sleep problems. The survey did find an increase during middle age, especially in women. But except for that , people reported that they felt their sleep quality improved as they got older. Old people may be happier probably because   _
A. their children have grown up.
B. they don't have to work every day.
C. they can do whatever they like best.
D. they are most likely satisfied with life.
Answer: