You Are the Manager of a Firm That Produces Output

You are the manager of a firm that produces output in two plants.The demand for your firm's product is P = 78 − 15Q,where Q = Q₁ + Q₂.The marginal costs associated with producing in the two plants are MC₁ = 3Q₁ and MC₂ = 2Q₂.What price should be charged in order to maximize revenues?

A) $39
B) $47
C) $52
D) $56