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: Surgery
[{'content': 'Which of the following is not a risk factor for oropharyngeal carcinoma? \nSelect and explain. \nA. Chronic hypertrophic candidiasis, B. Oral submucous fibrosis, C. Erythroplakia, D. None of the above', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Leukoplakia.\nErythroplakia.\nSubmucous fibrosis.\nLichen planus\nLaryngeal keratosis\nActinic cheliosis\nSmooth,red tonque of plummer - vinson syndrome.', 'role': 'assistant'}]