Roger Owns a Small Health Store That Sells Vitamins in a Perfectly

Multiple Choice

Roger owns a small health store that sells vitamins in a perfectly competitive market. If vitamins sell for $12 per bottle and the average total cost per bottle is $11.50 at the profit-maximizing output level, then in the long run

A) more firms will enter the market.
B) some firms will exit from the market.
C) the equilibrium price per bottle will rise
D) average total costs will rise.