(S)
Price
P₁
----------
P₁₂ -----------
Q₁
Q,
S-MSC=MPC
D=MPB
Quantity
Which of the following identifies the socially optimal output and price level?
O P1 and Q1
P1 and Q3
OP2 and Q2
O P₂ and Q3
P2 and Q4
MSB