The Figure Below Shows Revenue and Cost Curves of a Natural

The figure below shows revenue and cost curves of a natural monopoly firm.Figure 14.1
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In the figure,
D: Demand curve
MR: Marginal revenue curve
MC: Marginal cost curve
ATC: Average total cost curve
-According to Figure 14.1, in order to attain allocative efficiency, the regulatory body must attempt to set the price equal to:

A) P₂.
B) P₃.
C) P₁.
D) P₄.
E) P₅.