Which of the Following Practices Are, at Least in Part

Multiple Choice

Which of the following practices are, at least in part, attempts to reduce moral hazard problems?

A) The income of waiters and waitresses depends heavily on tips.
B) An employer pays below equilibrium wages because he thinks his employees are not working as hard as they could be.
C) The professors leaves the room to prevent cheating on exams.
D) Tenure professors are not supervised closely.