Answer:
c) degree of myelination of the axon
Explanation:
The myelin sheath covers many axons in central nervous system (CNS) ( by oligodendrocytes) and in the peripheral nervous system (PNS) (by Schwann cells). Their function is to insulate axons and to increase the speed at which information travels from one nerve cell to another.
Nerve conduction velocity is specific to each individual and depend on the level to which that axon is myelinated, but also on an axon's diameter.