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': "Blount's disease is - \nSelect and explain. \nA. Genu valgurn, B. Genu varum, C. Genu recurvatum, D. Meniscal injury", 'role': 'user'}, {'content': "Answer: B \nExplanation: Blount's disease is a rare growth disorder that affect children, causing the legs to bow outwards just below the knee.\nTibia vara is caused by growth retardation of the medial and posterior part of the proximal tibial epiphysis and epiphysis due to abnormal weight - bearing stress and compression forces on varus knee.", 'role': 'assistant'}]