Which of the following best describes the role of oxygen in combustion?

Oxygen plays a critical role in combustion by supporting the reaction. During combustion, a chemical reaction occurs between a fuel (such as wood, gasoline, or natural gas) and oxygen. This reaction releases energy in the form of heat and light. Oxygen is not the fuel itself, nor does it act as a catalyst; instead, it is essential for the ignition and sustenance of the combustion process. Without an adequate supply of oxygen, the combustion reaction would not be able to continue, even if there is a fuel present.

In contrast, the other options present different concepts related to combustion. While oxygen is vital for combustion to occur, it neither serves as the fuel itself nor functions as a catalyst that would accelerate a reaction without being consumed. Furthermore, oxygen does not cool the reaction; rather, it facilitates the exothermic process of combustion, which produces heat. Thus, the most accurate description of oxygen's role in combustion is that it supports the reaction.