Source: Parra, E

Source: Parra, E. J., Kittles, R. A., & Shriver, M. D. (2004) . Implications of correlations between skin color and genetic ancestry for biomedical research. Nature Genetics, 36, S54-S60.
-The graphs shown indicate the range of melanin amounts in populations from four different geographic regions. Of these populations, population D is likely most adapted for

A) having enough vitamin D to produce strong bones.
B) being protected against skin cancer.
C) preventing the breakdown of folate (folic acid) .
D) having very active melanin-producing cells.