In an Oligopoly, Cooperation Between Firms Usually Leads to Higher

Multiple Choice

In an oligopoly, cooperation between firms usually leads to higher profits than defecting. In spite of this, cooperation doesn't usually occur because:
I. it is illegal.
II. there is an incentive for each firm to cheat on an agreement to cooperate.
III. an oligopolistic firm will typically prefer lower profits for itself if the only way to make higher collective profits in the industry is to improve the profit position of its rivals.

A) I only
B) II only
C) I and II
D) II and III