It is definently All of the above because all of them have been advancements over the years
Answer: Endocrine system
Explanation: The integumentary system is that is made up of the skin, hair, nails and the Endocrine glands. The following functions of the integumentary system are:
a. It protects skin from any form of damage which could be in form dehydration.
b. It protects the skin by secreting an hormone called melanin which protects the skin from ultra violet radiation.
c. The integumentary system helps in regulating and maintaining the body temperature
d. The skin which is part of the integumentary system secretes Vitamin D which is an essential in building of strong and healthy bones.
Depending on where the population is, natural selection varies. Hope this helps :-)
B, since it needs somewhere to reside.
