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 mechanisms by which fluoride increases caries resistance include all of the following except- \nSelect and explain. \nA. Reduction in enamel solubility, B. Decreased rate of post-eruptive maturation, C. Interference with plaque microorganisms, D. Modification in tooth morphology', 'role': 'user'}, {'content': 'Answer: B \nExplanation: The benefits of fluoride in the reduction of dental caries have been known for years, but\xa0 its\xa0 exact\xa0 mechanism\xa0 of\xa0 action\xa0 is not completely understood. The mechanisms by which fluoride increases caries resistance may arise from both systemic and topical applications\xa0 of\xa0 fluoride. A\xa0 number\xa0 of proposed mechanisms have been identified which are assumed to work simultaneously and can be grouped as follows;\xa0\n1. Increase enamel resistance (or) Reduction in enamel solubility\xa0\n2. Increased rate of post-eruptive maturation\xa0\n3. Remineralization of incipient lesions\xa0\n4. Interference with plaque microorganisms\xa0\n5. Modification in tooth morphology.', 'role': 'assistant'}]