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: Dental
[{'content': 'Which part of the instrument should remain parallel\n(whenever possible) to the long axis of the tooth? \nSelect and explain. \nA. Blade, B. Cutting edge, C. Handle, D. Shank', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]