Explanation:

- Option 1: Benzenoid Compounds

- These are a type of aromatic compounds containing one or more benzene rings.

- Not considered aliphatic as they contain aromatic structures.

- Option 2: Aromatic Compounds

- Compounds that contain conjugated ring systems with delocalized electrons.

- Typically involve benzene rings, not aliphatic.

- Option 3: Cyclic Compounds

- These have atoms connected in a closed loop or ring.

- Not necessarily aliphatic; they can be aromatic or non-aromatic.

- Option 4: Acyclic Compounds

- Aliphatic compounds that do not have rings.

- Consist of open-chain structures, making them aliphatic.

- This is the correct answer.

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