The pigment that causes the blue color in the blue-footed boobies feet is…

A Vitamin D
B Carotenoid
C Chlorophyll

Carotenoid is the pigment that makes the blue-footed booby’s feet blue, which the bird obtains from its fresh fish diet. The bird may lose the brightness of the blue color in its feet if it’s food-deprived.

The correct answer is Carotenoid.