Myelin is a lipidic substance that covers the axons of the neurons, like the plastic covering an electrical wire, allowing the electrical impulses to travel faster along the axon.
The myelin sheath is formed by a series of segments, with uncovered sections called nodes of Ranvier, where the axon is exposed and the electric impulse is regenerated, so it can reach its target.
This means C) to speed transmission of neural impulses, is the right answer.
