If Firms in a Perfectly Competitive Industry Are Earning an Economic

If firms in a perfectly competitive industry are earning an economic profit,then in the ________,firms will ________ the industry.

A) short run; enter
B) long run; enter
C) short run; exit
D) long run; exit
E) More information about the firms' costs and the price of the product is needed to determine if firms enter or exit the industry.