Mike and Molly Snuffy are riding on a bus past a park where a group of motorcyclists are parked and relaxing. Mike smiles and fondly remembers his uncle giving him rides on a motorcycle. Molly shudders, remembering the motorcycle gang that used to terrorize her neighborhood. The difference in their emotional reactions is BEST explained by the concept of _____________.

a. gender differences

b. affect

c. critical thinking

d. social expectations