Answer:
d. social costs of government failure
Step-by-step explanation:
Social costs are those costs associated with production of a goods or services which are not accounted for by the free market . These costs are not compensated by the market . Pollution produced by the car in the atmosphere is a social costs which is not accounted for in the cost of manufacturing car . cost of displacing human population for building a dam is a social cost of building dam . They are not compensated by the market.
In the given case , all the costs given are associated with government failure which leads to lead contamination . These costs are not accounted for in the production cost of the goods . So they are social cost.