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: Pediatrics
[{'content': 'Most common cause of genu valgum in children is – \nSelect and explain. \nA. Osteoarthritis, B. Rickets, C. Paget disease, D. Rheumatoid arthritis', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]