-The Above Figure Shows Three Possible Average Total Cost Curves

Multiple Choice

-The above figure shows three possible average total cost curves.If all firms in a perfectly competitive industry each have an average total cost curve identical to ATC?,each produces 20 units,and the market price of the good is $16 per unit,then

A) the firms make an economic profit of $8 per unit.
B) firms will enter the industry and the number of firms increases.
C) the firms' ATC curves will eventually shift to become the same as ATC?.
D) firms will exit the industry and the number of firms decreases.
E) Both answers A and B are correct.