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: Unknown
[{'content': 'An infant presents with lethargy, frontal bossing and bowing of legs.  X-ray shows widening of epiphysis.  What is the diagnosis? \nSelect and explain. \nA. Scurvy, B. Rickets, C. Osteomalacia, D. Osteopetrosis', 'role': 'user'}, {'content': 'Answer: B \nExplanation: (Refer: Nelson’s Textbook of Paediatrics, 19th edition, pg no:199)', 'role': 'assistant'}]