A Firm Produces a Product at a Fixed Marginal Cost

Multiple Choice

A firm produces a product at a fixed marginal cost of $2 and sells the product on two different markets (A and B) . The demand on market A is Q_A = 10 - P. The demand on market B is Q_B = 20 - P. What quantity should the firm sell on market A?

A) 4
B) 6
C) 9
D) None of the above is correct.