Question

what are the primary products of the combustion of a hydrocarbon?
a carbon dioxide and water
b carbon dioxide only
c carbon dioxide and hydrogen
d carbon monoxide and water

Explanation:

Hydrocarbons are compounds made of carbon and hydrogen. When they undergo complete combustion (in the presence of sufficient oxygen), the carbon combines with oxygen to form carbon dioxide ($CO_2$) and the hydrogen combines with oxygen to form water ($H_2O$).

Answer:

A. carbon dioxide and water