A suitable solvent for iodine and naphthalene is

Explanation: Both iodine (\(\ce{I2}\)) and naphthalene (\(\ce{C10H8}\)) are non-polar substances. The rule of solubility is “like dissolves like,” meaning non-polar solutes dissolve best in non-polar solvents. Among the options:

• Water: polar solvent → not suitable.
• Carbon(IV) sulphide (CS₂): non-polar solvent → very good solvent for iodine and naphthalene.
• Benzene: also non-polar and would dissolve them, but CS₂ is the classic solvent used.
• Ethanol: polar due to –OH group → not ideal.

Final Answer: carbon(IV) sulphide (CS₂)