The Duopolists Carl and Simon Face a Demand Function for Pumpkins

The duopolists Carl and Simon face a demand function for pumpkins of Q = 8,200 - 400P, where Q is the total number of pumpkins that reach the market and P is the price of pumpkins. Suppose further that each farmer has a constant marginal cost of $.50 for each pumpkin produced. If Carl believes that Simon is going to produce Q_s pumpkins this year, then the reaction function tells us how many pumpkins Carl should produce in order to maximize his profits. Carl's reaction function is

A) R_C(Q_s) = 4,000 -.
B) R_C(Q_s) = 8,200 - 400Q_s.
C) R_C(Q_s) = 8,200 - 800Q_s.
D) R_C(Q_s) = 2,000 -.
E) R_C(Q_s) = 6,000 - Q_s.