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': 'The following study was conducted to check anticariogenic effect of fluoride EXCEPT \nSelect and explain. \nA. Dutch study, B. Newburg-Kingston study, C. Evauston-Oak study, D. Shoe-Leather survey', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]