The government is considering constructing flood defences. Costs: private $450m, external $60m. Benefits: private $260m, external $190m. Based on cost-benefit analysis, which decision and explanation is correct?
- ABuild. External benefits are greater than external costs.
- BBuild. Social benefits are greater than private benefits.
- CDo not build. Private costs are greater than the external benefits.
- DDo not build. Social costs are greater than the social benefits.