Answer:
some firms will exit from the market
Step-by-step explanation:
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 $12.50 at the profit-maximizing output level, then in the long run some firms will exit from the market
A perfectly competitive market consist of many buyers and sellers, different products and perfect information about the price of a good.
Option A. is correct.