The fundamental reason why cartels are unstable and tend to break down due to firms cheating on the cartel agreement is:
a. the marginal revenue of an individual firm in the cartel is equal to the marginal revenue of the cartel as a whole
b. the marginal revenue of an individual firm in the cartel is less than the marginal revenue of the cartel as a whole
c. the marginal revenue of an individual firm in the cartel is greater than the marginal revenue of the cartel as a whole
d. the Chain Store Paradox induces firms to produce less output than their cartel share
