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': 'Massive bleeding per rectum in a elderly patient is due to \nSelect and explain. \nA. Colitis, B. Ca.colon, C. Diverticulosis, D. Peptic ulcer disease', 'role': 'user'}, {'content': 'Answer: C \nExplanation: MCC of massive bledding per rectum is diverticulosis.', 'role': 'assistant'}]