Which of the following hydrocarbons belongs to the benzene family?

Toluene is a hydrocarbon that belongs to the benzene family, specifically classified as an aromatic hydrocarbon. Aromatic hydrocarbons are characterized by the presence of one or more benzene rings in their molecular structure. The structure of toluene consists of a methyl group (–CH₃) attached to a benzene ring, which gives it distinct properties and makes it a member of the benzene family.

In contrast, ethyne is an alkyne, characterized by its triple bond between carbon atoms, which does not include a benzene ring. Propanone, commonly known as acetone, is a ketone with a different functional group and does not fit into the benzene family. Methanol is an alcohol and contains a hydroxyl group (–OH) rather than a benzene ring. Thus, toluene is the correct choice as it embodies the characteristics of compounds belonging to the benzene family.