Concept:Myelin sheath is a fatty insulating layer around axons that speeds up nerve impulse transmission. Not all neurons require it; neurons carrying signals over very short distances often lack it.
Explanation:Sensory neurons and motor neurons transmit impulses over long distances between the body and the central nervous system.
To ensure rapid signal conduction, their axons are usually covered with myelin sheath.
Intermediate neurons, also called interneurons, are located entirely within the brain and spinal cord.
They connect sensory and motor neurons over very short distances.
Because the distance is so short, interneurons generally do not need myelin sheath for fast conduction.
Therefore, among the options, intermediate neurons may not have myelin sheath.
Answer:B. Intermediate neurons