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: Pathology
[{'content': 'In a granuloma epithelioid cells are giant cells and derived from \nSelect and explain. \nA. T lymphocytes, B. Monocyte-macrophages, C. B lymphocytes, D. Mast cells', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]