The correct answer is C. Cetyl alcohol.
Cetyl alcohol is a long-chain alcohol that is effective at reducing evaporation. It is a white, waxy solid that is soluble in water and ethanol. Cetyl alcohol is used in a variety of products, including cosmetics, lotions, and hair products. It is also used as a food additive and as a lubricant.
Methyl alcohol, ethyl alcohol, and butyl alcohol are all short-chain alcohols that are not as effective at reducing evaporation as cetyl alcohol. Methyl alcohol is a colorless, flammable liquid that is used as a solvent and as a fuel. Ethyl alcohol is the alcohol found in alcoholic beverages. Butyl alcohol is a colorless, flammable liquid that is used as a solvent and as a fuel.
Cetyl alcohol is the most suitable chemical which can be applied to the water surface for reducing evaporation because it is a long-chain alcohol that is effective at reducing evaporation. It is a white, waxy solid that is soluble in water and ethanol. Cetyl alcohol is used in a variety of products, including cosmetics, lotions, and hair products. It is also used as a food additive and as a lubricant.