Which of the following is true of the kinked demand model of​ oligopoly?
A. Each firm believes that if it lowers its price the other firms will follow​ suit, but if it raises its price the other firms will not raise their prices.
B. Each​ firm's marginal revenue curve is discontinuous at its current level of output.
C. The model predicts price rigidity. For​ example, the firms may not change their prices when marginal costs change.
D. All of the above are true.