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
Most common disease of human body is: 
Select and explain. 
A. Gingivitis, B. Hypertension, C. Diabetes, D. Dental caries
D: Dental caries
Answer: D: Dental caries 
Explanation: Dental caries, the most common disease in the mouth, is also the most common disease of the entire body. The first step in treating this disease is to identify it, and radiology is one of the best tools available to do so.