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: Medicine
[{'content': 'A 45-year-old man, known case of chronic renal failure develops rugger jersey spine. The probable cause it - \nSelect and explain. \nA. Aluminium intoxication, B. Secondary hyperparathyroidism, C. Osteoporosis, D. Osteomalacia', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]