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': 'An area of rarefaction  in the lower premolar area indicates \nSelect and explain. \nA. definite pathology., B. torus  mandibularis., C. possible mental foramen., D. root fracture.', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]