What Part of an Overhead Projector Would Be Most Like

What part of an overhead projector would be most like the myelin found in the brain?

A) The insulation covering the extension cord, as this insulation helps transmit the electrical energy more efficiently
B) The light bulb, as myelin becomes highly active when it receives energy
C) The reflecting mirror, as the purpose of myelin is to reflect away neurotransmitters
D) The long arm holding up the reflecting mirror, as the main function of the myelin is as a conduit through which electrical chemical energy flows within the neuron