The Diagram Below Shows the Short-Run Cost Curves for 3

The diagram below shows the short-run cost curves for 3 perfectly competitive firms in the same industry. FIGURE 9-6
-Refer to Figure 9-6.Given that Firms A,B and C are in the same industry,is this industry in long-run equilibrium?

A) No,because Firm A is not producing at a profit-maximizing level of output.
B) No,because if the industry were in equilibrium,all 3 firms would be earning zero economic profits.
C) Yes,because all 3 firms are producing at their minimum average total cost.
D) Yes,because P = MC = MR for each of the 3 firms.
E) Yes,because each of the 3 firms is operating at its minimum efficient scale.