How does sunscreen work?

1. It helps UV waves be able to pass through the air
2. It helps UV waves be able to pass through the skin
3. It helps prevent the skin from absorbing UV waves
4. It helps prevent the skin from reflecting UV waves

The correct answer is number 3. Sunscreen helps prevent the skin from absorbing UV waves. Sunscreen contains active ingredients that either absorb or reflect the UV radiation, acting as a barrier between the skin and the sun. These ingredients work by absorbing the UV rays and then converting them into less harmful forms of energy, such as heat. This prevents the UV radiation from penetrating the skin and causing damage.