Final answer:
Polyethylene glycol is a substance commonly used in moisturizing creams to protect and lubricate mucous membrane surfaces.
Step-by-step explanation:
The correct pair in this question is C) Polyethylene glycol; protect and lubricate mucous membrane surfaces. Polyethylene glycol is a substance commonly used in moisturizing creams due to its ability to retain moisture and form a protective barrier on the skin's surface, helping to alleviate itching and inflammation. It acts as a humectant, attracting and retaining water, which helps to hydrate the skin. Its viscosity also provides lubrication, making it easier to apply the cream and spread it evenly.