Multiple choice The velocity of an action potential propagation is independent of an axon diameter depends on the compactness of the myelin sheath surrounding the axon remains unaffected if the axon of a nerve cell losses myelin is the fastest in unmyelinated axons Reveal answer Fill a bubble to check yourself B Correct answer Explanation The above option is correct as the velocity of conduction action potential propagation is the fastest in large diameter myelinated axons.