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': "The modified Mayo score used in clinical trials to assess the severity of: \nSelect and explain. \nA. Ulcerative colitis, B. Crohn's disease, C. Diveiculosis, D. Pancreatitis", 'role': 'user'}, {'content': "Answer: A \nExplanation: Modifications of the original Truelove and Witts' criteria are used in daily practice, the modified Mayo score is used in current clinical trials. The mayo score uses: Stool frequency Rectal bleeding Mucosal appearance in endoscopy Physician's global assessment Ref: Journal of Crohn's and Colitis (2012) 6, 965-990", 'role': 'assistant'}]