The diagram illustrates the cost and benefit curves for a good in a free market. Which combination is correct?
- Aactual output level: P1Q1; social optimal level of output: P3Q3
- Bactual output level: P2Q2; social optimal level of output: P3Q3
- Cactual output level: P2Q2; social optimal level of output: P4Q4
- Dactual output level: P3Q3; social optimal level of output: P4Q4