Refer to the Accompanying Table,where Q Represents the Quantity Produced,internal

Refer to the accompanying table,where Q represents the quantity produced,internal cost and external cost are given for various quantities,and P represents the price consumers are willing to pay for various quantities to answer the following questions.

-The social optimum occurs where price is ________ and quantity is ________.

A) $4; 6
B) $8; 4
C) $10; 3
D) $10; 5
E) $12; 6