The government must decide on the most suitable of four routes for constructing a new railway line. The advantages and costs of each route are given in $m in the table. Which route should be selected?
- Aprivate benefit 600, external benefit 600, private cost 100, external cost 150
- Bprivate benefit 700, external benefit 600, private cost 150, external cost 200
- Cprivate benefit 800, external benefit 500, private cost 100, external cost 150
- Dprivate benefit 900, external benefit 700, private cost 200, external cost 300