Other things equal,if more firms enter a monopolistically competitive industry:

A) the demand curves facing existing firms would shift to the right.
B) the demand curves facing existing firms would shift to the left.
C) the demand curves facing existing firms would become less elastic.
D) losses would necessarily occur.

In a monopolistically competitive industry, firms have differentiated products, which means that they have some market power. When more firms enter the industry, the number of close substitutes for existing firms' products increases, which leads to a decrease in their market power. As a result, the demand curves facing existing firms shift to the left because consumers have more choices and are less willing to pay a premium price for their products. This increased competition also makes it harder for firms to earn profits, which means that some firms may experience losses.