Correct Answer: B
Explanation:
The central nervous system is made up of two types of tissue: the grey matter and the white matter.
The grey matter is mainly composed of neuronal cell bodies and unmyelinated axons. Axons are the processes that extend from neuronal cell bodies, carrying signals between those bodies. In the grey matter, these axons are mainly unmyelinated, meaning they are not covered by a whitish-colored, fatty protein called myelin.
The grey matter serves to process information in the brain. Structures within the grey matter process signals generated in the sensory organs or other areas of the grey matter. This tissue directs sensory (motor) stimuli to nerve cells in the central nervous system where synapses induce a response to the stimuli. These signals reach the grey matter through myelinated axons that make up the bulk of the white matter in the cerebrum, cerebellum and spine.
Also found in the grey matter are the glial cells (astroglia and oligodendrocytes) and capillaries. The glial cells transport nutrients and energy to the neurons and may even influence how well the neurons function and communicate. Because axons in the grey matter are mainly unmyelinated, the greyish hue of the neurons and glial cells combine with the red of the capillaries to give this tissue its greyish-pink color (after which it is named).