I’d say D. The cost of treatment becomes more affordable than with medical insurance because treatment is extremely expensive and medical insurance lowers the cost.
Melanin provides pigmentation to the skin and it also provides UV ray protection (which is its role in the epidermis).
The temperature of tropical areas relative to places more distant to the equator. Another reason why is higher nutrient cycling, which is also an effect of higher temperature.
Because there are other liquids in your body it passes through and it adds to the amount of water.
