The correct answer is C. Sodium or potassium salts of heavier fatty acids.
Soaps are sodium or potassium salts of heavier fatty acids. They are made by reacting sodium hydroxide (lye) with animal or vegetable fats. Soaps are used to clean because they are able to dissolve both water and oil. When soap is added to water, it forms tiny bubbles called micelles. The oil and dirt are attracted to the oil-loving part of the micelle, and the water is attracted to the water-loving part of the micelle. This allows the soap to lift the dirt and oil away from the surface being cleaned.
Option A is incorrect because soaps are not salts of silicates. Silicate salts are salts that contain silicon and oxygen. Soaps do not contain these elements.
Option B is incorrect because soaps are not mixtures of glycerol and alcohols. Glycerol is a sugar alcohol, and alcohols are organic compounds that contain one or more hydroxyl groups. Soaps do not contain these compounds.
Option D is incorrect because soaps are not esters of heavy fatty acids. Esters are compounds that are formed when an alcohol reacts with an acid. Soaps are not formed in this way.