When Raphael Was in the Elevator, He Couldn't Help but Notice

When Raphael was in the elevator, he couldn't help but notice a man and a woman in conversation. He decided that the woman in the suit was probably a college administrator and the gray-haired man in the glasses was probably a professor. Raphael was engaged in a process called:

A) implicit cognition.
B) hindsight bias.
C) the bystander effect.
D) social categorization.