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: Medicine
[{'content': 'Distal colitis with respect to ulcerative colitis refers to: \nSelect and explain. \nA. Proctitis, B. Left sided colon distal to splenic flexure is only involved, C. Mid transverse colitis, D. None of the above', 'role': 'user'}, {'content': "Answer: B \nExplanation: Distribution of ulcerative colitis: 1. Proctitis - involvement limited to the rectum 2. Distal colitis - Left-sided involvement limited to the colon distal to the splenic flexure 3. Pancolitis -Extensive involvement extends proximal to the splenic flexure, including pancolitis This classification known as the Montreal classification Ref: Journal of Crohn's and Colitis (2012) 6, 965-990.", 'role': 'assistant'}]