Final answer:
Humans protect themselves from excessive sun exposure using sunscreen, sunglasses, and shade umbrellas. These methods protect against immediate skin damage and long-term health risks like skin cancer. The correct answer is d. all of these.
Step-by-step explanation:
Humans protect themselves from too much sun exposure by several means which can include: wearing sunscreen, putting on sunglasses, and using shade umbrellas. Sunburn is a burn to the skin caused by overexposure to UV radiation from the sun's rays or tanning beds, and it can lead to long-term health issues, such as eye damage or skin cancer. Therefore, the correct answer to the question is d. all of these. The effectiveness of sunscreen lies in its ability to protect skin against immediate damage and the long-term risk of skin cancer, as it blocks harmful UV B rays with wavelengths of 280-320 nm. The development of a suntan is actually the body's defense mechanism to protect living skin cells from UV exposure by producing pigments, despite it often being misinterpreted as a healthy look. To best safeguard against the dangers of sun exposure, one should employ all recommended forms of protection whenever spending time outdoors.