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: Medicine
[{'content': "Pigment gallstones usually not seen in: \nSelect and explain. \nA. Gilbe's syndrome, B. Alcoholic cirrhosis, C. Cystic fibrosis, D. Clofibrate therapy", 'role': 'user'}, {'content': "Answer: D \nExplanation: Clofibrate therapy: Increased biliary secretion of cholesterol, leads to cholesterol gallstones. Pigment stones are more common in patients who have chronic hemolytic states), liver cirrhosis, Gilbe's syndrome, or cystic fibrosis. Reference: Harrisons Principles of Internal Medicine, 18th Edition, Page 2618", 'role': 'assistant'}]