On the graph, Q represents the quantity of plastics and P represents the price of plastics. TP 32+ 28 24+ Social Cost 20 16 Private Cost 12 Demand 100 200 300 400 500 In order to reach the social optimum, the government could impose a tax of $2 per unit on plastics. O impose a tax of $6 per unit on plastics. impose a tax of $8 per unit on plastics. offer a subsidy of $6 per unit on plastics