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': 'Radiographically the level of the normal inter proximal alveolar crest is related to the \nSelect and explain. \nA. Position of cemento - enamel junctions of the approximal teeth, B. Epithelial attachment, C. Anatomy of the alveolar process, D. Location of the Gingival attachment', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]