$$\text { Quantity }$$ -Use the Above Figure $P _ { 1 }$

$$\text { Quantity }$$
-Use the above figure.The profit-maximizing price will be

A) $P _ { 1 }$ .
B) $P _ { 2 }$ .
C) $\mathrm { P } _ { 3 }$ .
D) $\mathrm { P } _ { 4 }$ .