Monopolistically competitive firmsGroup of answer choiceshave market power because they can set price above marginal cost.have no market power because they earn zero economic profit.have no market power because of free entry.have no market power because price equals marginal cost.

Monopolistically competitive firms have market power because they can set price above marginal cost.

Here's why:

1. Monopolistically competitive firms sell differentiated products: This means that each firm has its own unique product, which is not exactly like the products of other firms. This gives them some control over the price of their product.

2. They face downward sloping demand curves: Because each firm's product is unique, it has some degree of market power. This means that it can raise its price without losing all of its customers. This gives the firm the ability to set its price above marginal cost.

3. They can earn positive economic profits in the short run: Because these firms can set their price above marginal cost, they can earn positive economic profits in the short run. However, in the long run, new firms will enter the market, which will drive down prices and eliminate these profits.

4. Free entry and exit: While new firms can freely enter and exit the market, this does not eliminate a firm's market power. Instead, it simply means that profits will be driven down to zero in the long run. But even then, each firm retains some market power because of product differentiation.

So, monopolistically competitive firms do have market power because they can set price above marginal cost.