What common effect does sunlight exposure have on the skin?

Sunlight exposure commonly causes pigmentation changes in the skin due to the activation of melanocytes, the cells responsible for producing melanin, which gives color to the skin. When UV rays from the sun reach the skin, they stimulate these melanocytes to increase melanin production in an attempt to protect deeper layers of the skin from damage. This response can lead to various pigmentation changes, such as tanning or the development of sunspots and age spots.

The other choices appear less accurate in reflecting the typical impact of sunlight on the skin. For example, while some might think sunlight could enhance skin texture or improve hydration, prolonged exposure generally leads to skin damage, including rough texture and dryness. Similarly, while moderate sun exposure might support Vitamin D synthesis, it does not significantly increase collagen production in the long term; rather, excessive sun exposure can degrade collagen and elastin, contributing to premature aging. Thus, option C accurately represents the most common effect of sunlight on skin health.