Which of the following is an example of a reason why firms might pay efficiency wages?

A  At equilibrium wages, workers sleep when the boss is not looking because workers are not deeply concerned about being fired.

B  At equilibrium wages, only minimally qualified workers apply for the job.

C  At equilibrium wages, workers often quit to find better jobs.

D  d. At equilibrium wages, workers cannot afford a healthy diet so they fall asleep at work due to a lack of energy.

E  At equilibrium wages, workers often quit to find better jobs, workers sleep when the boss is not looking because workers are not deeply concerned about being fired, workers cannot afford a healthy diet so they fall asleep at work due to a lack of energy, and only minimally qualified workers apply for the job