The answer is D. It <span>keeps outside substances away from the receptor cells</span>
It needs at least 4 hours to grow to cause illness :)
The hole reason for natural selection is to keep the Eco system in balance take something away it will fall apart or if you put to much of something the same thing will happen.
The theory of evolution is a shortened form of the term “theory of evolution by natural selection,” which was proposed by Charles Darwin and Alfred Russel Wallace in the nineteenth century