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
An area of rarefaction  in the lower premolar area indicates 
Select and explain. 
A. definite pathology., B. torus  mandibularis., C. possible mental foramen., D. root fracture.
C: possible mental foramen.
Answer: C: possible mental foramen. 
Explanation: None