This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Endocrinology, Subject name: Medicine
[{'content': 'Which of the following is associated with secondary hyperparathyroidism - \nSelect and explain. \nA. Parathyroid adenoma, B. Marked hypercalcemia, C. Chronic renal failure, D. Parathyroidectomy relieves the symptoms', 'role': 'user'}, {'content': 'Answer: C \nExplanation: severe secondary hyperparathyroidism occurs due to hypercalcemia associated with renal failure (Harrison 17 pg 2387)', 'role': 'assistant'}]