Contrary to the popular belief, human skin color gradient is not governed by sunburn or even skin cancer; instead, complexion is shaped by conflicting demands from two essential vitamins: folate, which is destroyed by the sun’s ultraviolet radiation, and vitamin D, which the skin produces after exposed to those same rays.
A) folate, which is destroyed by the sun’s ultraviolet radiation, and vitamin D, which the skin produces after exposed to those same rays- WRONG as "exposed" is not used correctly.
B) folate, which the sun’s ultraviolet radiation destroyed, and vitamin D, which the skin produced after being exposed to those same- WRONG as produced is not right here.
C) folate, which is destroyed by the sun’s ultraviolet radiation, and vitamin D, which is produced by the skin after it is exposed to those same rays- CORRECT as exposed used correctly and it refers to skin.
D) destroyed by the sun’s ultraviolet rays, folate, produced by the skin after it is exposed to those same rays, vitamin D- WRONG
E) the sun’s ultraviolet radiation destroys folate and the skin after it is exposed to those same rays produces vitamin D- WRONG