This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Large intestine, Subject name: Surgery
[{'content': 'Best investigation to diagnose colonic diveiculosis \nSelect and explain. \nA. Barium enema, B. CT Scan, C. Ultrasound, D. MRI', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Investigation of choice for colonic diveiculosis: Barium enema Investigation of choice for diveiculitis: CT scan', 'role': 'assistant'}]