In Multiple Sclerosis, the Myelin Sheaths Around the Axons of the Brain

Multiple Choice

In multiple sclerosis, the myelin sheaths around the axons of the brain and spinal cord are damaged and demyelination results. How does this disease manifest at the level of the action potential?
I.Action potentials move in the opposite direction on the axon.
II.Action potentials move more slowly along the axon.
III.No action potentials are transmitted.

A) only I
B) only II
C) only III
D) only II and III