Which factors contribute to the ideal use of a fuel in various applications, considering availability, cost, combustion properties, and environmental effects?
S1: High calorific value and low ignition temperature.
S2: Low cost and easy availability.
S3: Minimal environmental impact.
S4: High density and viscosity.
1
S1 and S2
2
Only S2 and S4
3
S1, S3, and S4
4
Only S1, S2, and S3