Figure 10-3 A graph of price versus quantity. A line labeled supply, private cost, goes up and to the right. A line labeled demand, private value, goes down and to the right and intersects the supply line at a point corresponding to Q_market on the horizontal axis. A right arrow from Q_market points to Q_optimum, and a similar arrow points to the right from the demand line to a parallel line labeled social value. A downward arrow points to a triangle formed by a vertical line through Q_market, the supply line, and the social value line. Refer to Figure 10-3. What is this market experiencing? a positive production externality a positive consumption externality a negative consumption externality a negative production externality