Answer:
I believe the answer is "C. When your cells need more oxygen."
Please mark brainliest, if right. Thanks :)
The investigators could distinguish human hair from animal hair by the patter of pigmentation and by the medullary index.
The pigmentation in human hairs is denser toward the cuticle, whereas in animal hair is denser toward the medulla. Human hairs are usually one colour throughout the whole length, while animal hairs may change colour suddenly.
The medulla in humans is thinner than in animals: the medullary index for human hairs is 0.33 or less; the medullary index for animal hairs is 0.5 or more.
Answer: The nervous system acts like a highway that transmits information to and from the brain. It communicates what parts of the body might need or not need certain things so that they can be sent to their respective destinations.
