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': 'Cause of hypophosphatemic rickets - A/E ? \nSelect and explain. \nA. Vit D deficiency, B. CRF, C. X-linked hypophosphatemic rickets, D. Fanconi syndrome', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. is 'b' i.e., CRF", 'role': 'assistant'}]