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': 'Bonded retainers are popular in which area of dentition? \nSelect and explain. \nA. Lower anteriors, B. Lower posteriors, C. Upper anteriors, D. Upper posteriors', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]