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: Radiology
The presence of pulp stones on the radiograph of a tooth
indicates the presence of 
Select and explain. 
A. Acute pulpitis, B. Acute pulpalgia, C. Chronic periodontitis, D. None of the above
D: None of the above
Answer: D: None of the above 
Explanation: None