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 with air shadows absent in distal bowel coils on X-ray abdomen is characteristic of \nSelect and explain. \nA. Duodenal webs, B. Duodenal atresia, C. CHPS, D. All of the above', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. Duodenal atresia', 'role': 'assistant'}]