Answer:
E. very dark
Explanation:
In a geographical area where the UV radiation is maximal, the population living there will have a very dark skin. The reason for this is that that population will constantly be exposed to the more intense UV radiation. This will cause the pigmentation to become darker and darker in order for the population to avoid serious skin conditions that can be fatal. The darker the skin color, the more resilient it will be to the effects of the UV radiation, as the darker skin is much more resistant to the UV radiation, thus the risks of skin conditions and burns will be minimized. This can easily be seen in practice, as the populations with the darkest skin color all live in Africa, in spaces that are arid and semi-arid, where the UV radiation is high, and there's lack of shelter from it.