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': 'Best investigation to diagnose hemorrhoids is \nSelect and explain. \nA. Proctoscopy, B. DRE, C. Barium enema, D. USG', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Proctoscopy is IOC for hemorrhoids.', 'role': 'assistant'}]