Human skin colour is an example of

The correct option is B Quantitative inheritance
Quantitative inheritance is the inheritance of a character (known as a quantitative character or quantitative trait) that depends upon the cumulative action of many genes, each of which produces a small effect. Examples of such quantitative characters include clutch size in birds, milk production in cattle, weight and skin pigmentation in humans, spore production in ferns, height of trees, and nectar production in buttercups.