This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Miscellaneous (Small & Large Intestine), Subject name: Surgery
[{'content': "Collar Button Ulcer is a feature of - \nSelect and explain. \nA. Crohn's Disease, B. Ischaemic Colitis, C. SigmoidVolvulus, D. Ulcerative colitis", 'role': 'user'}, {'content': "Answer: D \nExplanation: Ans. is 'd' i.e., Ulcerative colitis o Repeat from previous sessions", 'role': 'assistant'}]