Which of the following is NOT an example of consumer behavior consistent with the standard assumptions of microeconomic theory?

A. People are less likely to leave tips at restaurants that they are unlikely to visit again.

B. Waiters and waitresses have an incentive to provide good service in order to earn tips.

C. Due to the convention of tipping, restaurants pay a lower wage to waiters and waitresses than they would in the absence of any tipping rule.

D. Although tipping reduces the amount of income available for purchasing goods, people usually leave tips at restaurants.

E. none of the above