Which of the following statements is true?

a. Monopoly results in smaller output and a higher price than would be the case under perfect competition.

b. The monopolist produces at an output where P > MC and the marginal value to society of the last unit produced is greater than its marginal cost.

c. The monopoly is not producing enough output from society’s standpoint.

d. Monopoly may lead to greater concentration of economic power and could retard innovation.

e. All of the above statements are true.