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 colorless or transparent pit and fissure sealants are usually \nSelect and explain. \nA. Indicated only in case of rampant caries, B. Accepted even though retention is limited, C. Limited to buccal pits, D. Indicated only before six years of age', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]