What happens to the skin when exposed to UV light?

When the skin is exposed to UV light, it reacts by increasing the production of melanin, a pigment responsible for the color of our skin. This process occurs as a protective mechanism to shield deeper layers of the skin from the damaging effects of UV radiation. As melanin production increases, the skin darkens, resulting in a tan. This tanning signifies the body's effort to defend itself against UV exposure, as increased melanin can help absorb and dissipate some of the harmful effects of sunlight.

The other options reflect different skin conditions or responses that may occur due to various factors but are not directly caused by UV exposure in the manner described. For example, while UV exposure can lead to wrinkles over time through skin damage, the immediate response to UV light is the tanning effect due to heightened melanin production.