An aromatic hydrocarbon is best described as which of the following?

• A. Hydrocarbon with at least one triple bond
• B. Saturated alkane with no rings
• C. Hydrocarbon consisting of closed rings of carbon atoms
• D. Non-aromatic compound with a benzene ring

Answer: (C)

Aromatic hydrocarbons are defined by cyclic, conjugated ring systems in which π electrons are delocalized around the ring, giving extra stability and planarity. The description that a hydrocarbon consists of closed rings of carbon atoms fits this key structural feature—the rings provide the framework for the delocalized electrons seen in aromatic systems like benzene. The other ideas miss this essential ring/conjugation picture: a triple bond points to alkynes rather than aromatics; a saturated alkane with no rings has no conjugation or π system; and a non-aromatic compound with a benzene ring would contradict the actual aromatic stabilization of that ring.