The Figure Below Illustrates the Cost and Revenue Structure for a Monopoly

The figure below illustrates the cost and revenue structure for a monopoly firm.
Figure 11-17

Refer to Figure 11-17. If the monopoly firm is currently producing Q₃ units of output, then a decrease in output will necessarily cause profit to

A) remain unchanged.
B) decrease.
C) increase as long as the new level of output is at least Q₂.
D) increase as long as the new level of output is at least Q₁.