This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Anatomy
Which of the following is not an example of macroglia? 
Select and explain. 
A. Schwann cells, B. Oligodendrocytes, C. Astrocytes, D. None of the above
D: None of the above
Answer: D: None of the above 
Explanation: There are three types of macroglia: oligodendrocytes, Schwann cells, and astrocytes Ref: Ganong's Review of Medical Physiology 23rd edition, Chapter 4.