A regional environmental authority is evaluating two sustainable energy proposals: 'Project Canopy' (a biomass and afforestation initiative) and 'Project Solaria' (a community solar farm array). The table below details the estimated costs and benefits of both projects.
| Cost/Benefit category | Project Canopy (£ million) | Project Solaria (£ million) |
|---|---|---|
| Private costs | 50 | 80 |
| Private benefits | 65 | 110 |
| External costs | 14 | 22 |
| External benefits | 25 | 43 |
The authority intends to approve the project that yields the higher ratio of social benefits to social costs. This chosen ratio (correct to one decimal place) is
1.3:11.3:11.3:1
1.4:11.4:11.4:1
1.5:11.5:11.5:1
1.6:11.6:11.6:1
