The correct option is D All of the above
Neuroglial cells—usually referred to simply as glial cells or glia—are quite different from nerve cells. The major distinction is that glia do not participate directly in synaptic interactions and electrical signaling. However, it is now known that glia play an active role in many central homeostatic processes and also during development. Four main types of glia exist, namely astrocytes, oligodendrocytes, ependymal cells and microglia.