Franco participated in an experience sampling study of emotional experience. The participants in the study ranged in age from 18 to 90. He wore a pager, and every time he was paged he checks off the emotions he was experiencing at that moment on a list. Franco and others in his age group reported that positive emotions lasted longer than for the other study participants, but they reported that negative emotional states ended more quickly. What age group is Franco most likely to be in?

a. The youngest group (18 to 25).
b. The middle-aged group (35 to 55).
c. The oldest group (65 and up).
d. There is no reliable age difference in emotional experience.