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: Physiology
Function of microglia in CNS 
Select and explain. 
A. Phagocytosis, B. Myelin synthesis, C. Fibrosis, D. All of the above
A: Phagocytosis
Answer: A: Phagocytosis 
Explanation: Microglia in CNS has phagocytic activity.