Which of the following is true of the findings of studies on explanatory styles?
a. Stressful life experiences can decrease the level of optimism in an individual.
b. People under age 35 tend to have a more optimistic explanatory style than those over 65.
c. Contrary to pessimists, optimists pay attention to positive stimuli only.
d. Younger optimists also tended to underreport their weight, whereas elderly optimists claimed the opposite.