Which fuel is the least polluting?

Which fuel is the least polluting?
Past Papers: PMS Combined Competitive Examination — Past Paper MCQs
A: Petrol
B: Natural gas
C: Diesel
D: Coal

Natural gas emits fewer pollutants than petrol; diesel; or coal; making it the least polluting fossil fuel. This property guides energy policies; key for studying environmental sustainability; climate change mitigation; and cleaner energy alternatives in modern contexts.