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: Surgery
[{'content': 'The commonest cause of colonic obstruction in neonates is - \nSelect and explain. \nA. Meconium ileus, B. Aganglionic colon, C. Beal atresia, D. Volvulus', 'role': 'user'}, {'content': "Answer: B \nExplanation: Option 'a & c' are causes of small bowel obstruction, not colonic obstruction\nA most common cause of Intestinal obstruction in a neonate is Intestinal atresia — p. 1133, 1232 Nelson", 'role': 'assistant'}]