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
[{'content': 'Most common disease of human body is: \nSelect and explain. \nA. Gingivitis, B. Hypertension, C. Diabetes, D. Dental caries', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Dental caries, the most common disease in the mouth, is also the most common disease of the entire body. The first step in\xa0treating this disease is to identify it, and radiology is one of the best tools available to do so.', 'role': 'assistant'}]