Explanation:

- C6H6 is a chemical formula representing benzene, a colorless and highly flammable liquid with a sweet smell.

- Option 4: Benzene is the correct answer.

- Option 1: Methanol (CH3OH) is an alcohol, also known as wood alcohol, used as a solvent and antifreeze.

- Option 2: Acetic acid (CH3COOH) is the main component of vinegar.

- Option 3: Acetone (C3H6O) is a solvent commonly used in nail polish remover.

- Benzene is important in the production of various chemicals and has a ring-like structure.