Answer:c. include glial cells
Explanation:
Glial cells are neuroglia found in the brain and spinal cord; where they perform nutrition functions, tissues homeostatic function, and formation of myelin sheath.
They are higher in number than neurons.
They also provide support for nervous transmission in neurons.
From above, glial cells are NEUROGLIA of the CNS, and not associated with RED BLOOD CELLS IN THE BONE MARROW.