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': "Most common cause of genu valgum in children is - \nSelect and explain. \nA. Osteoarthritis, B. Rickets, C. Pager's disease, D. Rheumatoid arthritis", 'role': 'user'}, {'content': "Answer: B \nExplanation: Commonest type of genu valgum is idiopathic.\nAmongst the given options, most common cause of genu valgum in children is rickets.\nPaget's disease causes genu varum.\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\nOA and RA are not seen in children.", 'role': 'assistant'}]