The Empirical Literature on Monopsony Has Found

The empirical literature on monopsony has found:

A) Where it exists, monopsony power seems to endure over the long run.
B) Although one might expect to see monopsony power in markets for nurses and teachers, studies have failed to find this effect.
C) There is evidence of monopsony power in certain labour markets.
D) It appears as though many labour markets are affected by monopsony power.
E) All of the answer choices are correct.