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': "Siffert katz sign seen in \nSelect and explain. \nA. Chondromalacia patella, B. Blount's disease, C. CTEV, D. Rocker Bottom foot", 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]