The Following Graph Shows the Demand and Cost Curves of an Imperfectly

The following graph shows the demand and cost curves of an imperfectly competitive firm. MC and ATC represent the marginal cost curve and the average cost curve respectively.Figure 9.1
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-According to Figure 9.1, what is the firm's profit when it sells quantity Q₁ at price P₁?

A) Rectangle ABCD
B) Rectangle DCEF
C) Rectangle ABEF
D) Distance AB
E) Distance FD