Which industry is least likely to be a source of sulfur dioxide pollution?

Hazardous waste incinerators primarily handle the burning of waste materials, which can include various chemicals and compounds that may release several types of pollutants, including sulfur dioxide. However, the key point here is that among the listed options, hazardous waste incineration typically involves the combustion of waste that may contain low levels of sulfur compared to the other industries mentioned.

Power plants, particularly those that burn coal or oil, are significant sources of sulfur dioxide due to the high sulfur content of fossil fuels. Natural gas extraction can also produce sulfur compounds, especially if the gas has a high sulfur content initially. Automobile manufacturing, while not a direct source, can contribute to sulfur dioxide emissions through the combustion of fuels in vehicles during their operation.

Considering these factors, hazardous waste incineration generally poses a lesser risk for sulfur dioxide emissions compared to the other industries listed, making it the least likely source of this pollutant. This understanding emphasizes the need to assess the specific processes and fuel types involved in each industry when evaluating their potential environmental impact.