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': 'H.I.V. periodontitis is \nSelect and explain. \nA. diagnostic of H.I.V. infection, B. characterized by remissions and exacerbations, C. characterized by necrosis and periodontal destruction, D. periodontitis is not seen in H.I.V. infection', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]