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': 'Ulcerative colitis stas in : \nSelect and explain. \nA. Descending colon, B. Transverse colon, C. Caecum, D. Rectum', 'role': 'user'}, {'content': "Answer: D \nExplanation: Ans. is 'd' i.e. Rectum", 'role': 'assistant'}]