Low Levels of Vitamin D Have Been Linked to Seasonal

Low levels of vitamin D have been linked to seasonal affective disorder,a condition that leads to depression in the winter.Would you expect dark-skinned people to be more or less prone to seasonal affective disorder?

A) Dark-skinned people are probably less likely to have this disorder because they tend to eat foods that are higher in vitamin D.
B) Dark-skinned people are probably less likely to have this disorder because they have evolved enzymes that are more efficient at producing vitamin D.
C) Dark-skinned people are probably more likely to have this disorder as the pigments in their skin block out the sunlight needed to make vitamin D.
D) Dark-skinned people are probably more likely to have this disorder because the pigments in their skin allow sunlight to pass and destroy vitamin D that has been obtained through diet.