This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Adrenal Gland, Subject name: Pathology
[{'content': "In a chronic smoker which hemoptysis, he also gave a history of hypeension and obesity. Lab data showed raised ACTH levels, which are not suppressed by dexamethasone. The cause of Cushing's syndrome in the patient is - \nSelect and explain. \nA. MEN1, B. Pituitary adenoma, C. Adrenal coical adenoma, D. Ectopic ACTH secreting tumor", 'role': 'user'}, {'content': 'Answer: D \nExplanation: - History of chronic smoking and hemoptysis along with raised ACTH levels not suppressible by dexamethasone points to ectopic ACTH producing small cell carcinoma of lung.', 'role': 'assistant'}]