Answer:
b. Neuron
Step-by-step explanation:
Neurons are one of the two types of cells that together make the nervous system. Neurons and neuroglia together make the nervous system. Neurons are not a type of neuroglial cell. Neurons are structural and functional units of the nervous system.
Most of the neurons have three parts: the metabolic center "cell body", short extensions "dendrites" and long extension "axon". Function of neurons is to propagate nerve impulse.