The correct answer is: D. Low octane fuel
Lead is a heavy metal that is toxic to humans and other animals. It was once used as an additive in gasoline to improve its performance, but it was banned in the United States in 1996 due to its health risks.
Coal is a fossil fuel that is made up of carbon and other elements. It is used to generate electricity and to produce steel. Coal does not contain lead.
Cooking gas is a mixture of propane and butane. It is used to cook food and to heat homes. Cooking gas does not contain lead.
High octane fuel is a type of gasoline that is designed to resist engine knocking. It is used in high-performance engines. High octane fuel does not contain lead.
Low octane fuel is a type of gasoline that is designed for use in lower-performance engines. It is less expensive than high octane fuel, but it is more likely to cause engine knocking. Low octane fuel does contain lead.