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': 'The cause of nephrocalcinosis in systemic granulomatous disease is: \nSelect and explain. \nA. Overproduction of 1,25 dihydroxy vitamin D, B. Dystrophic calcification, C. Mutation in calcium sensing receptors, D. Increased reabsorption of calcium', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Nephrocalcinosis is deﬁned as calciﬁcation of the renal interstitium and tubules. It is associated with\xa0hypercalcemia, which occurs due to overproduction of vitamin D.', 'role': 'assistant'}]