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': 'During abutment preparation for overdenture, which of the following is more preferable? \nSelect and explain. \nA. Short copings, B. Long copings, C. Bare root surface, D. None of the above', 'role': 'user'}, {'content': 'Answer: C \nExplanation: A bare root surface can provide adequate long term service for both immediate and replacement overdentures and is the selection of choice.', 'role': 'assistant'}]