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: Ans. is 'b' i.e., X-ray abdomen", 'role': 'assistant'}]