What is the purpose of a catalytic converter?

The purpose of a catalytic converter is to transform exhaust gases into harmless substances. This essential component of a vehicle's exhaust system uses chemical reactions to convert harmful pollutants such as carbon monoxide, hydrocarbons, and nitrogen oxides into less harmful emissions, primarily carbon dioxide and nitrogen.

While option D mentions oxidation of hydrocarbons, which is part of the catalytic converter's function, it does not encompass the full breadth of what the converter does. The catalytic converter not only promotes oxidation but also facilitates reduction reactions that convert other harmful emissions. This holistic approach to improving air quality makes option B the most accurate representation of the catalytic converter's main purpose.

In contrast, options A and C misinterpret the function of the catalytic converter, as it does not directly affect fuel collection or drive the engine. Therefore, understanding the catalytic converter’s role in reducing harmful emissions is fundamental for those studying fire investigation and automotive systems.