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': "Which of the following is not associated with Crohn's disease: March 2005 \nSelect and explain. \nA. Fistula, B. Stricture, C. Sclerosing cholangitis, D. None", 'role': 'user'}, {'content': 'Answer: D \nExplanation: Ans. None of the option', 'role': 'assistant'}]