What is the function of sebum?

The function of sebum is primarily related to maintaining the health and integrity of the skin. When sebum mixes with sweat, it contributes to forming the acid mantle, which is a thin film of fatty acids and lactic acid that serves as the skin's protective barrier. This barrier is crucial for maintaining skin hydration and preventing water loss. It also plays an important role in protecting the skin from external irritants and pathogens.

While sebum does have a role in protecting against bacterial growth, its more immediate function is in the formation of the acid mantle. The acid mantle’s slightly acidic pH helps to inhibit the growth of harmful bacteria and fungi on the skin’s surface, thereby safeguarding the skin. Thus, option B accurately captures the partnership of sebum and sweat in creating this critical protective layer, emphasizing the significance of sebum in skin health and protection.