Concept:Petroleum is separated by fractional distillation, which works on differences in the boiling points of its fractions.
Explanation:Crude oil is heated, so different hydrocarbons vaporise at different temperatures.
Inside a fractionating column, each fraction condenses at its own boiling point range.
Lower boiling point fractions collect at the top, while higher boiling point fractions condense near the bottom.
Therefore, the separation of petroleum fractions depends on differences in boiling points, not on melting points, molar masses, or solubilities.
Answer:D. boiling points