The demand curve faced by a firm with a patent on a marketable product

One way to view the cost structure of monopolistic competition is to say that the cost of product differentiation is equal to

A) the difference between marginal revenue and marginal cost. B) the difference between the cost of production for a monopolistically competitive firm in an open market and the minimum average total cost. C) the sum of price and marginal cost. D) the sum of marginal cost and minimum average cost.

Because of easy entry, monopolistically competitive firms will

a. produce at the lowest average total cost b. charge a price equal to marginal cost c. earn no economic profit in the long run d. take advantage of all economies of scale e. earn no economic profit in the short run