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
The modified Mayo score used in clinical trials to assess the severity of: 
Select and explain. 
A. Ulcerative colitis, B. Crohn's disease, C. Diveiculosis, D. Pancreatitis
A: Ulcerative colitis
Answer: A: Ulcerative colitis 
Explanation: 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