This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Genetics And Genetic Disorders, Subject name: Pediatrics
[{'content': 'Commonest cause of intestinal obstruction in Down syndrome is: \nSelect and explain. \nA. Colonic atresia, B. Intestinal atresia, C. Duodenal atresia, D. Esophageal atresia', 'role': 'user'}, {'content': "Answer: C \nExplanation: c. Duodenal atresia(Ref: Nelson's 20/e p 610-615, Ghai 8/e p 637-639)Most common cause of Intestinal obstruction in Down's syndrome is duodenal atresia.", 'role': 'assistant'}]