Which if the following causes least pollution when burnt:a. Petrolb. Natural Gasc. Coald. Diesel

Among the options provided, natural gas (option b) generally causes the least pollution when burnt compared to the other options. Natural gas is often considered a cleaner-burning fuel compared to coal, petrol (gasoline), and diesel. When burned, natural gas emits fewer pollutants such as carbon dioxide (CO2), sulfur dioxide (SO2), nitrogen oxides (NOx), and particulate matter compared to other fossil fuels like coal and oil-based products.

It's important to note that while natural gas is relatively cleaner than other fossil fuels, it is not entirely devoid of environmental impacts. The extraction, transportation, and processing of natural gas can still have environmental consequences, and its combustion still releases carbon dioxide, contributing to greenhouse gas emissions and climate change. However, when it comes to immediate air quality and local pollution concerns, natural gas combustion tends to have a lower impact than the combustion of other fossil fuels.