Polly Worked as a Bartender

Polly worked as a bartender. A few people used to wave money toward her so that she would serve them first. She used to find this to be rude and hence, either ignored them or always served them last. People realized that she serves only the people who wait politely, and then their rude behavior stopped. This implies that Polly used the model of _____.

A) positive reinforcement
B) negative reinforcement
C) variable ratio reinforcement
D) extinction
E) shaping