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 on X-ray is seen in – \nSelect and explain. \nA. Duodenal atresia, B. Oesophageal atresia, C. Colonic atresia, D. Pyloric stenosis', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]