Evolution, it mentioned over several generations.
B. because only amoebas use the false foot or pseudopodia
The spinal cord is located in the vertebral foramen and is made up of 31 segments: 8 cervical, 12 thoracic, 5 lumbar, 5 sacral and 1 coccygeal. A pair of spinal nerves leaves each segment of the spinal cord.
This role would be the organisms niche. None of the other choices make any sense. A nesting site is not a role, a biomass is not a role, and territorial range is not the role an animal has in its community. A niche is an organisms role in its community, how it interacts with the things around it, where it lives and what it does.