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: Radiology
[{'content': 'A patient complains of epigastric pain, radiating to back off and on. The investigation of choice is – \nSelect and explain. \nA. MRI, B. CT scan, C. USG, D. Radio nucleotide scan', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Epigastric pain radiating to back suggests the diagnosis of acute pancreatitis. CECT is the investigation of choice for pancreatitis.', 'role': 'assistant'}]