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': 'Radiographs are of great value in diagnosing periodontal\ndisease because they reveal \nSelect and explain. \nA. Hard - to - soft tissue relationship, B. Morphology of bone deformities, C. Presence of pockets, D. Thickening of the lamina dura', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]