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.
B. their fuction is a result of their shape and folding
I believe the most appropriate is a selective medium and differential medium. Selective medium types are formulated to support the growth of one group of organism, but inhibit the growth of another. Blood agar is a differential medium that distinguishes bacterial species by their ability to break down the red blood cells included in the media. Blood agar is often used to distinguish between the different species of pathogenic streptococcus bacteria.