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': 'Most common cause of colonic obstruction is ? \nSelect and explain. \nA. Volvulus, B. Hernia, C. Adhesions, D. Neoplasm', 'role': 'user'}, {'content': "Answer: D \nExplanation: Ans. is 'd' i.e., Neoplasm", 'role': 'assistant'}]