Assuming That the Total Market Size Remains Constant,a Monopolistically Competitive

Assuming that the total market size remains constant,a monopolistically competitive firm earning profits in the short run will find the demand for its product decreasing in the long run because

A) new entrants into the market are more likely to have cutting-edge products.
B) as the firm raises its price in the long run, it will lose some customers to new entrants in the market.
C) some of its customers will have switched to purchasing the products of new entrants in the market.
D) its costs of production rise.