What is the primary function of collagen in skin?

Collagen plays a crucial role in maintaining the structure and firmness of the skin. It is a protein that forms a significant part of the dermal layer, providing support and strength to the skin's framework. This structural integrity is essential for the skin's overall appearance and health, as it helps maintain elasticity and resilience. When collagen levels are adequate, the skin appears plump and youthful; however, as collagen production decreases with age or environmental factors, the skin can start to lose its firmness, leading to sagging and wrinkles. Thus, option C accurately reflects the primary function of collagen in the skin.