The government is thinking about constructing flood defences along a river. It has worked out the costs and benefits as shown. Using cost-benefit analysis, which decision and explanation about flood defences 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.