The Following Figure Shows the Demand and Marginal Revenue (MR)

Multiple Choice

The following figure shows the demand and marginal revenue (MR) curves faced by a monopolist.

-Refer to the figure above.What is the profit-maximizing quantity that the monopolist should produce if it faces a constant marginal cost of $3?

A) 200 units
B) 300 units
C) 400 units
D) 600 units