[单项选择] The way people hold to the belief that a fun-filled, pain free life equals happiness actually reduces their chances of ever attaining real happiness. If fun and pleasure are equal to happiness then pain must be equal to unhappiness. But in fact, the opposite is true: more often than not, things that lead to happiness involve some pain. As a result, many people avoid the very attempts that are the source of true happiness. They fear the pain inevitably brought by such tings as marriage, raising children, professional achievement, religious commitment (承担的义务), self-improvement. Ask a bachelor (单身汉) why he resists marriage even though he finds dating to be less and less satisfying. If he is honest he will tell you that he is afraid of making a commitment, for commitment is in fact quite painful. The single life is filled with fun, adventure, excitement. Marriage has such moments, but they are not its most distinguishing features. Couples with infant children are lucky t
A. Because he believes that single life is more cheerful than a married one.
B. Because he is unwilling to take on family responsibilities.
C. Because he enjoys dating very much.
D. Because he is afraid of losing all his fun adventure and excitement.