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': 'Investigation of choice in peptic ulcer perforation is - \nSelect and explain. \nA. USG, B. X-Ray abdomen, C. Paracentesis, D. CT scan', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]