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: Pathology
[{'content': 'Causes of nephrocalcinosis are - \nSelect and explain. \nA. Hyperparathyroidism, B. T.B. Kidney, C. Hypercalcemia, D. All', 'role': 'user'}, {'content': "Answer: D \nExplanation: Ans. is 'a' i.e., Hyperparathyroidism; 'b' i.e., T.B. Kidney; 'c' i.e., Hypercalcemia", 'role': 'assistant'}]