This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nervous system, Subject name: Physiology
[{'content': 'Macrophage is CNS \nSelect and explain. \nA. Fibrous Astrocyte, B. Microglia, C. Oligodendrocyte, D. Protoplasmic astrocyte', 'role': 'user'}, {'content': "Answer: B \nExplanation: Microglia are scavenger cells in CNS that resemble tissue macrophages and remove debris resulting from the injury. Ganong's review of medical physiology; 23rd edition; pg: 80", 'role': 'assistant'}]