Which answer would score higher? Not sure where to start? Explain this Answer A Limited oxygen causes incomplete combustion, producing carbon monoxide and soot. Sulfur in the fuel burns to form sulfur dioxide, while high temperature lets nitrogen and oxygen from the air react to form oxides of nitrogen. Answer B Limited oxygen causes incomplete combustion, producing carbon monoxide and soot. Sulfur in the fuel burns to form sulfur dioxide, while high temperature causes oxides of nitrogen to form in the kiln flame.