Consider three rms, A, B and C, all producing kilos of potatoes (per year) in a perfectly competitive market. The diagrams below show marginal cost curves for each of the three rms. FinnA FimB Quantity Cost (5) Cost (3) Cost (S) 200 500 700 500 800 900 200 500 800 Quantity of potatoes Quantity 131' potatoes Quantity of potatoes a) Suppose each of Firms A, B, and C are producing 500 kilos of potatoes. Is Firm A productively efficient? Why