Answer:D. astrocytes
Step-by-step explanation:
glial cell are any of several types of cell that function primarily to support neurons its divided into four groups namely oligodendrocytes,
astrocytes, microglia, and ependymal cells. The astrocytes plays a key role in regulating ions, uptake and/or breakdown of some neurotransmitters, and contribute to the formation of the blood-brain barrier.