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': 'The file which has a non-cutting side is \nSelect and explain. \nA. K-files, B. Safety K-files, C. Hedstrom files, D. Safety Hedstrom files', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]