What is the purpose of sunscreen?

The purpose of sunscreen is primarily to block ultraviolet rays, which is crucial for protecting the skin from sun damage, including sunburn, premature aging, and an increased risk of skin cancer. Sunscreens contain active ingredients that either absorb, reflect, or scatter the sun's harmful UV radiation.

While it can be true that some sunscreens have reflective properties, their main function is to provide a barrier against UV rays. This protection is essential for maintaining skin health and preventing long-term damage. Thus, choosing sunscreen primarily for its ability to block UV radiation aligns with its fundamental purpose. The other options relate to different aspects of skin care but do not address the primary function of sunscreens in UV protection.