Final answer:
Emollients are fatty agents that moisturize and protect the skin by forming an oily layer on its surface to prevent water loss. The correct option is b.
Step-by-step explanation:
Emollients are substances that soften and moisturize the skin and decrease itching and flaking. They are almost always fatty agents which act by providing a layer of oil on the surface of the skin to prevent water evaporating from the skin surface.
Some of the common emollients include petrolatum, cocoa butter, lanolin, liquid paraffin, and various oils. It's important to understand that moisturizers can be made up of water, oils, emulsifiers such as cetearyl alcohol, and thickening agents to create different forms such as lotions, creams, and ointments.
The primary functions are to protect, moisturize, and lubricate the skin, closely mimicking the protective sebum produced by healthy skin.
Therefore, the correct option is b.