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A fertilizer factory when processing fertilizers also produces waste that pollutes the town's water reserves. Figure 2 presents the demar value) and supply (private cost) for the fertilizer market. The negative externality from the factory activity is estimated at 200$ per ton. a): What is the social optimal price and quantity of fertilizer? [1 mark] b): How can the government help to achieve the social optimal outcome? Briefly discuss [1 mark] Figure 2 Price Supply, private cost 1350 1250 200 150 HDD Demand, private value Quantity in tons. O 20 40 66 80 /DD / 20 140 Paragraph EC