(figure 67-5: profit maximization in monopolistic competition) if other firms see economic profits in the industry, they will enter it, and the demand curve for firms already in the industry will shift to the ; in the long run, this will result in economic profit and price .
a right;=0; ATC b. right;>0;> ATC c. left; <0; <4TC d. left: 0; ATC e. left;=0;> ATC