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: Orthopaedics
[{'content': 'Perthes disease etiology  is \nSelect and explain. \nA. Pyogenic, B. Tubercular, C. Traumatic, D. Unknown', 'role': 'user'}, {'content': 'Answer: C \nExplanation: thought be due to an inflammatory disease secondary to trauma or some other developmental disorder.\nmost widely accepted theory are those involving interruption of vascular supply to femoral head.', 'role': 'assistant'}]