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': 'Using pit and fissure sealant is: \nSelect and explain. \nA. Specific protection, B. Early diagnosis and treatment, C. Secondary prevention, D. Limitation of disability', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]