In the combustion of hydrocarbon, carbon monoxide is formed. What has occurred?

Which clue can be used to identify a chemical reaction as a combustion reaction?

Which clue can be used to identify a chemical reaction as a combustion reaction? Oxygen is a product. A hydrocarbon reacts with oxygen. Water and carbon dioxide react. The reaction involves ions.

Rapid oxidation of a substance, accompanied by the production of heat and light.

If combustion is to be initiated and sustained, all of the following elements must be present except