Bart's friends convinced him to join them in smashing decorative pumpkins early one Halloween evening. Later that night he did not resist their pressures to throw eggs at passing police cars. Bart's experience best illustrates the?

Foot-in-the-door phenomenon.

Explanation:

Foot-in-the-door phenomenon: In psychology, the phenomenon of foot-in-the-door is referred to as the process of making a small request from someone initially to make the person agrees later on for a big request. It gives an idea that if an individual agrees for a small request then he or she might agree for the bigger one as well.

Example: A child request to get a small toy from his or her parents and then, later on, ask for a cycle.

In the question above, Bart's experience best illustrates the foot-in-the-door phenomenon.