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': 'Double bubble sign in an X-ray abdomen is indicative of: \nSelect and explain. \nA. Annular pancreas, B. Ileal atresia, C. Anal rectal malformation, D. All of the above', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. Annular pancreas', 'role': 'assistant'}]