Final answer:
A monopolistically competitive market is characterized by a large number of sellers offering differentiated products, which grants them some control over pricing.
Step-by-step explanation:
The characteristic of a monopolistically competitive market that is correct from the given options is a. A relatively large number of sellers producing differentiated products. This type of market is characterized by many firms that sell products that are similar yet not identical. These differentiated products can be distinguished by various features such as characteristics, location, intangible aspects, and consumer perceptions. Monopolistic competitors have some control over the selling price due to product differentiation, unlike perfect competitors. Although there are some barriers to entry and exit in monopolistically competitive markets, they are not as high as in oligopolistic markets. The demand curve for a monopolistically competitive firm is not perfectly elastic because the firm has some power to set its price thanks to product differentiation.