Answer:
D. always makes an economic profit
Explanation:
A monopolistically competitive markets consists of firms that sell differentiated products. In the market, there are free entry and free exist, but each firm enjoys a kind of monopoly its products which are the same to other products in the market but are different as a result of branding.
In the short run, the monopoly enjoys on the differentiated product enables the monopolistically competitive firm to make an economic profit. But due to free entry and exist in the market, the firm economic profit will be zero while it only make normal profit.