Choice "B" is correct. Monopolistic competition is characterized by a relatively large number of sellers who produce differentiated products. There are few barriers to entry and firms exert some influence over the price and the market. Best examples are brand name consumer products.
Choice "c" is incorrect. Relatively few sellers with differentiated products would indicate an oligopoly.
Choice "a" is incorrect. One company would be a monopoly, two an oligopoly.
Choice "d" is incorrect. A relatively large number of sellers and a standardized product indicates perfect competition.
