-In the Above Figure $S _ { 1 }$ Represents the Supply Curve Which Includes Private Costs,and

-In the above figure, $S _ { 1 }$ represents the supply curve which includes private costs,and $S _ { 2 }$
Is the supply curve which includes social costs.If the firm is producing a product that has external costs that the firm does have to pay,what will be the equilibrium price and quantity?

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