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': 'Basal bone is \nSelect and explain. \nA. That part of the bone embracing apices of root of teeth, B. Lower border of the mandible, C. Ramus of the mandible, D. That part of the bone containing teeth', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]