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': "Thumb print sign is seen in: March 2011 \nSelect and explain. \nA. Crohn's disease, B. Deal carcinoma, C. Ischemic colitis, D. Lymphoma of colon", 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ans. C: Ischemic colitis Earlier features of intestinal ischemia seen on abdominal radiographs include bowel wall edema, known as "thumb printing". Radiological signs in GIT: Thumb printing sign: Ischemic colitis Bird of prey sign: Sigmoid volvulus Double bubble sign (X-ray abdomen): - Annular pancreas - Duodenal atresia String sign: - Crohn\'s disease - Pyloric stenosis Single bubble sign: Pyloric stenosis Chain of lake appearance: Chronic pancreatitis Fox sign: Acute pancreatitis Widening of duodenal C loop: Carcinoma of head pf pancreas', 'role': 'assistant'}]