How Do Myelin Sheaths Increase the Speed with Which Action

Multiple Choice

How do myelin sheaths increase the speed with which action potentials are propagated along an axon?

A) They increase the permeability of Na+ ions in the plasma membrane.
B) They amplify the action potential by increasing sodium influx along the entire distance of the neuron.
C) They insulate the axon, preventing K+ ions from exiting the neuron.
D) They cause action potentials to "jump" down the axon rather than travel in a continuous path along every site on the axon.