What type of light does UVB radiation primarily affect?

UVB radiation primarily affects the epidermis, which is the outermost layer of skin. This type of radiation is known for its role in causing sunburn and is a significant factor in the development of skin cancer due to its ability to penetrate the epidermis and damage the DNA within skin cells. The impact of UVB is crucial because it primarily stimulates the production of melanin, leading to tanning as a protective response, and can induce the formation of various skin lesions.

On the other hand, the other options involve deeper structures or tissues. Subcutaneous layers are located below the epidermis and are not directly affected by UVB exposure. Hair follicles, while residing within the epidermis, are not the primary focus of UVB effects, as they are more influenced by other factors. Muscle tissue is situated even deeper and is not influenced by UVB radiation at all, as it is protected by the outer layers of the skin.

Understanding these distinctions highlights the specific interaction UVB has with the skin, reinforcing the importance of protecting the epidermis from harmful UV exposure.