Final answer:
Benzene (C₆H₆) is the aromatic compound among the options given because it contains a benzene ring with delocalized pi electrons, which is a characteristic feature of aromatic compounds.
Step-by-step explanation:
The student has asked which of the following compounds is aromatic: Benzene (C₆H₆), Ethanol (C₂H₅OH), Methane (CH₄), Acetic Acid (CH₃COOH).
The answer is Benzene (C₆H₆). Aromatic compounds are characterized by the presence of a benzene ring, which is a planar, cyclic ring of six carbon atoms with delocalized pi electrons. Benzene has a chemical formula of C₆H₆ and it meets the criteria for being aromatic because it contains a benzene ring with alternating single and double bonds that are delocalized, which is a distinctive feature of aromatic compounds. The other listed compounds, such as Ethanol, Methane, and Acetic Acid, do not contain this benzene ring structure and therefore are not considered aromatic.