Which best illustrates the relationship between variations within a population and natural selec- tion? A Natural selection acts upon a population since all members of the population are identical. B Organisms are able to change their genetic makeup to best adapt to a changing external environment. C Giraffes have long necks and legs from stretching to reach food in trees. This trait was then passed to their offspring. D Antelopes with muscular legs are able to outrun their predators better than antelopes with poor muscle tone. Thus they lived to reproduce.​ will give brianliest!!!