Cleaner fuels that should be used by industries and automobiles are:
All of these
Cleaner fuels produce very less pollutants as compared to the traditional fuels such as coal, wood etc. For example:
CNG (Compressed Natural Gas)
LPG (Liquefied Petroleum Gas)
Unleaded petrol - Petrol without lead. Initially petrol had lead, which on combustion in automobiles produced harmful lead oxides.