Question

Variations in human skin color:
a. Balance the dangers of exposure to sunlight with the need for vitamin D
b. Have no relationship to climate or geography
c. Are inversely related to the concentration of melanin: the greater the melanin, the lighter the skin
d. Are related to the distance of the equators: the closer to the equator, the lighter the skin color
e. Have clear and definite points of demarcation

Answer

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