1. The central nervous system including brain and spinal cord.
2. The peripheral nervous system including nerves coming out from the brain and spinal cord, i.e., cranial nerves and spinal nerves.
3. The autonomic nervous system including sympathetic nervous system and parasympathetic nervous system.
The answer is "B. Marsupials". Marsupials undergo relatively premature births compared to many other species, and although this puts the baby at risk, it lessens the risks for the mother.
Formed by erosion created by seafloor spreading
RIVER DELTAS ARE formed by erosion created by seafloor spreading
NOT:
caused by the movement of tectonic plates areas of infertile, rocky soil