单选题 Which of the following may contribute to a longer life span?

A、 Showing adequate trust instead of suspicion of others.
B、 Eating the food low in fat and driving with great care.
C、 Cultivating an optimistic personality and never losing heart.
D、 Looking on the bright side and developing a balanced level of risk.

【正确答案】 C

【答案解析】[解析] A项与倒数第二句的“疑惑心重的人比乐观豁达的人早逝”不相符；B项也不对，文中说eating the right foods并不等于低脂食物；C项提到的an optimistic personality和never losing heart都是a sunny disposition的特征；D项后半部分不对。故选C。