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: Physiology
[{'content': 'Pheochromocytoma is characterized by excessive secretion of: \nSelect and explain. \nA. Catecholamines., B. Glucocorticoids., C. Aldosterone., D. All of the above.', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Pheochromocytoma is the tumour of the adrenal medulla.', 'role': 'assistant'}]