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': 'Size of the bur for preparing lingual rest seat for an RPD \nSelect and explain. \nA. 1/10th inch, B. 1/4th inch, C. 1/2 inch, D. 1 inch', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]