The of the myelin sheath insulates neurons so messages are conducted more efficiently.

The high fat content of the myelin sheath insulates neurons so messages are conducted more efficiently.

Explanation:

The Myelin Sheath of a neuron consisting of high fat containing cells. A gap between the myelin sheath is called axon. The myelin sheath gives the whitish appearance to the white matter of the brain.  The fat inhibits the propagation of electricity, the signals jump from one gap to the next. Multiple sclerosis is characterized by patches of demyelination of the central nervous system. The symptoms of the result from this demyelination are determined by the functions normally contributed by the affected neurons, the Disruption of muscle control, speech and visual disturbances are common.

i believe the answer would be b. hope it : )