Answer the following question: I'm taking a test and have to guess the right answer to the question after the article. Article: Happiness pays off, studies show. Psychologists seeking the real secrets of happiness report that very happy people tend to be more _ and agreeable than less happy people. "Our findings suggest that very happy people have rich and satisfying social relationships and spend little time alone compared to average people," write psychologists Ed Diener and Martin E. P. Seligman in the journal Psychological Science. Solid social relationships do not promise happiness, but they are an important contributing factor. The very happy people whom the authors studied all said they had good quality social relationships. However, the authors write, there is no single key to high happiness. "High happiness seems to be like beautiful symphonic music--including many instruments, without any one being enough for the beautiful quality." Diener regards happiness as "subjective wellbeing"--in other words, the person evaluates his or her own quality of life. The question to ask is, "Is my life going well, according to the standards I choose to use?" If the answer is "yes", then that person is judged to be happy. Because people evaluate their lives based on happiness, subjective wellbeing is very important. Though necessary, it is not enough for having a good life. "Subjective wellbeing seems quite necessary for the 'good society', although it is not enough for that society because there are other things we also value and would want in such a place." says Diener. Can subjective wellbeing be measured scientificall? Diener points out three parts contributing to happiness: pleasant emotions and moods, lack of negative emotions and moods, and satisfaction judgment, to which other factors including cheerfulness and feelings of fulfillment may be added. There is no magic formula for happiness. Diener suggests steps you can take to ensure you are as happy as you can be. Surrounding yourself with good friends and family--people who care about you and whom you care about--is a start. Joining in activities you enjoy and value is also... Question: According to Diener, a person can be judged to be happy when he _ . Options: A: has rich and satisfying social relationships B: spends more time with other people C: joins in a lot of activities he enjoys and keeps himself optimistic D: thinks his life is going well according to his own standards
Answer:
D