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: Microbiology
[{'content': "Reactive tubercular ahritis: \nSelect and explain. \nA. Spina ventusa, B. Pott's disease, C. Poncet's disease, D. None", 'role': 'user'}, {'content': "Answer: C \nExplanation: Ans. is. 'c' i. e. Poncet's disease", 'role': 'assistant'}]