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: Surgery
[{'content': 'Causes for primary hyperparathyroidism \nSelect and explain. \nA. Parathyroid carcinoma, B. Renal failure, C. Rickets, D. Malabsorption', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]