This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Joint disorders, Subject name: Anatomy
[{'content': 'Deformity most commonly seen in primary osteoahritis of knee joint \nSelect and explain. \nA. Genu valgum, B. Genu recurratum, C. Genu varus, D. Procurvatum', 'role': 'user'}, {'content': 'Answer: C \nExplanation: In knee joint osteoahritis, medial joint space is affected earliest and causes assymetrical joint space narrowing This results in varus deformity Refer: maheswari 9th/e p 420', 'role': 'assistant'}]