This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Endocrinology and breast, Subject name: Anatomy
[{'content': 'Commonest cause for hyperparathyroidism is - \nSelect and explain. \nA. Single adenoma, B. Multiple adenomas, C. Single gland hyperplasia, D. Multiple gland hyperplasia', 'role': 'user'}, {'content': "Answer: A \nExplanation: Primary Hyperparathyroidism PHPT Arises from increased PTH production from abnormal parathyroid glands and results from a disturbance of normal feedback control exeed by serum calcium More common in women Solitary adenoma is the MC cause (in 80%) Parathyroid adenomas are most commonly located in Inferior parathyroid glands Increased PTH production leads to Hypercalcemia Increased GI absorption of calcium Reduced renal calcium clearance Increased production of vitamin D3 Ref: schwaz's principle of surgery 10th edition Pgno : 1560", 'role': 'assistant'}]