Liquefied Petroleum Gas is considered as cleanest fuel because of the following reasons: LPG has a high calorific value. The calorific value of LPG is about 50 KJ/g.It is very neat and clean domestic fuel. LPG burns with a blue smokeless flame and leaves no ash behind. So, it does not cause any pollution. Therefore, LPG is a clean fuel.It does not produce any poisonous gases on combustion.LPG is easy to handle and convenient to store.LPG is easy to handle and can be ignited almost instantaneously.Hence, the correct option is \\\\(D\\\\)