This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Parathyroid and adrenal glands, Subject name: Surgery
[{'content': 'Incidental finding in CT scan, a 3 cm adrenal mass, which of the following is not done? \nSelect and explain. \nA. Adrenalectomy, B. Dexamethasone suppression test, C. Measurement of catecholamines, D. Midnight plasma coisol', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Nonoperative therapy, with close periodic follow-up, is advised for lesions <4 cm in diameter with benign imaging characteristics, whereas adrenalectomy is recommended for lesions >=4 cm in size due to the increased risk of cancer.', 'role': 'assistant'}]