The horizontal axis labeled quantity, from the left shows Q 1 and Q 0. The vertical axis labeled price, from the bottom shows P 0 and P 1. The increasing supply curve labeled S 1 equals marginal social cost, passes through (Q 1, P 1). Another supply curve increasing from the same point on the vertical axis and labeled S 0 equals marginal private cost, passes through (Q 0, P 0). The decreasing demand curve labeled D equals marginal social benefit, passes through (Q 1, P 1) and (Q 0, P 0), interesting curve S 1 at (Q 1, P 1) and curve S 0 at (Q 0, P 0). negative externality changes socially optimal market equilibrium to Multiple choice question. P0 and Q0. P1 and Q0. P1 and Q1. P0 and Q1