Due to their function, nerve fibers which carry afferent impulses are known as afferent nerves or sensory nerves, and those nerve fibers which carry efferent impulses are known as efferent nerves or motor nerves.
C.
Biotic mean alive, so we can cut off the first 2 easily. Aquatic birds eat frogs, so that one is safe for now. A decrease in something parasitic usually helps the population, so D is out too. The only one left is C.
Cyanobacteria released OXYGEN into the atmosphere through photosynthesis
