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': "Penrose drain is \nSelect and explain. \nA. Simple rubber tube opens at one end, B. Simple rubber tube opens at both ends, C. Modified corrugated rubber drain, D. Modified Foley's Catheter", 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]