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': "'Saw tooth' appearance on barium enema may be seen in: March 2004 \nSelect and explain. \nA. Diveicular disease of colon, B. Carcinoma colon, C. Colitis, D. Polyps", 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. A i.e. Diveicular disease of colon', 'role': 'assistant'}]