Use the Following to Answer Question

Multiple Choice

Use the following to answer question:
Figure: Monopoly Profits in Duopoly
-(Figure: Monopoly Profits in Duopoly) Use Figure: Monopoly Profits in Duopoly.If there were two firms in this industry,they could engage in _____ and reap monopoly profits.

A) game theory
B) the prisoners' dilemma
C) collusive behavior
D) measuring the four-firm concentration ratio