Answer: Option (A) is the correct answer.
Step-by-step explanation:
When a mixture of two liquids with different boiling points are separated by heating then this process is known as fractional distillation.
For example, petroleum contains mixture of hydrocarbons, alkanes, aromatic hydrocarbons etc.
All these components of petroleum have different boiling point. Hence, they can be separated by fractional distillation.
Thus, we can conclude that in the process of fractional distillation, the components of petroleum are separated according to boiling point.