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
[{'content': 'Histiocytes are: \nSelect and explain. \nA. Scavenger cells, B. Allergic cells, C. Released in immunologic response, D. Leukocytes', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]