What substances are responsible for lubricating the skin?

Oils from sebaceous glands are the primary substances responsible for lubricating the skin. These natural oils, also known as sebum, play a crucial role in maintaining the skin's hydration and protective barrier. Sebum is produced by the sebaceous glands and helps to keep the skin moist, prevents excessive water loss, and protects against external irritants and pathogens. This lubrication is essential for healthy skin, as it helps to ensure that the skin remains supple and does not become dry or cracked.

While water is vital for overall skin health and hydration, it does not provide the same lubricating properties that oils do. Salts and alcohols, on the other hand, can be drying or irritating to the skin and do not serve the purpose of lubrication. Therefore, the oils produced by sebaceous glands are the key contributors to skin lubrication, making this the correct answer.