Why is UVB radiation often referred to as "burning rays"?

UVB radiation is often referred to as "burning rays" because it is primarily responsible for causing sunburn and contributes significantly to the development of skin cancer. When the skin is exposed to UVB rays, it can lead to direct damage to the DNA in skin cells, resulting in inflammation and the typical symptoms of sunburn, such as redness, tenderness, and peeling.

This type of radiation is most intense during the summer months and can cause immediate effects on the skin. In addition to its burning effects, prolonged and repeated exposure to UVB radiation can accumulate damage over time, which increases the risk of developing skin cancers, including melanoma. Hence, its designation as "burning rays" directly relates to its immediate and harmful effects on the skin.

The other options do not align with the primary action of UVB rays. While skin aging is often associated with UVA rays, promoting hydration and enhancing elasticity are not directly linked to UVB exposure. Therefore, the emphasis on burning and cancer risk is what distinguishes UVB radiation in this context.