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: Surgery
[{'content': 'Treatment of choice for simple cyst of liver \nSelect and explain. \nA. Percutaneous drainage, B. Deroofing, C. Observation, D. Aspiration', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Deroofing is the treatment of choice for simple cyst of liver.', 'role': 'assistant'}]