The Following Figure Shows the Revenue and Cost Curves of a Monopolist

The following figure shows the revenue and cost curves of a monopolist. Figure 10.3 D: Average Revenue
MR: Marginal Revenue
ATC: Average Total Cost
MC: marginal Cost
Consider the monopolist described in Figure 10.3.The firm can maximize profit by producing:

A) zero units.
B) Q₁ units.
C) Q₂ units.
D) Q₃ units.
E) Q₄ units.