Concept:Crude oil is a natural mixture of hydrocarbons, mainly belonging to the alkane family.
Methane is one of the alkane hydrocarbons found in crude oil and its associated gas.
Explanation:Crude oil contains hydrocarbons of different chain lengths.
The lighter, gaseous part of crude oil consists largely of methane (
CH4).
Methane is the simplest alkane and is a primary hydrocarbon constituent of crude oil.
Ethanol is not a hydrocarbon, so it is not a constituent of crude oil.
Therefore, among the given options, methane is the correct primary constituent.
Answer:D. Methane