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': 'Colon cut off sign is seen in \nSelect and explain. \nA. Acute pancreatitis, B. Chronic pancreatitis, C. Pancreatic carcinoma, D. Ulcerative colitis', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Colon cut off sign - Distension of the colon upto the transverse colon with a paucity of gas distal to splenic flexure - seen in Acute pancreatitis.', 'role': 'assistant'}]