Which type of UV rays account for up to 95 percent of UV radiation reaching the Earth's surface?

UVA rays account for up to 95 percent of UV radiation that reaches the Earth's surface. They have a longer wavelength compared to UVB and UVC rays, which enables them to penetrate the skin more deeply. This is significant because UVA rays are primarily responsible for photoaging and can initiate skin cancer by damaging the DNA in skin cells.

While UVB rays also contribute to skin damage and play a role in the development of skin cancers, they constitute a smaller proportion of the UV radiation that reaches us. UVC rays, on the other hand, are mostly absorbed by the Earth's ozone layer and do not normally reach the surface. The inclusion of UVAA in the choices may lead to confusion as it is not a recognized classification of UV radiation, reinforcing that UVA is indeed the correct answer regarding its prevalence and impact.