C) slate, a metamorphic rock
Answer: The correct answer is D. the central nervous system and the peripheral nervous system.
The nervous system is a complex system that is made up of nerves and nerve centers in different organisms that carries messages to and from the brain and the spinal cord to send them into various parts of the body.
It is primarily divided into-
1) CNS that is central nervous system ( made up of brain and spinal cord). The CNS is responsible for the voluntary functions of the body.
2) PNS that is peripheral nervous system ( possess cranial and spinal nerves arising from brain and spinal cord respectively). It controls the involuntary functions of the body.
