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': 'Treatment objective for serial extraction: \nSelect and explain. \nA. To intercept a developing arch-length deficiency and to reduce or eliminate the need for extensive appliance therapy, B. Reduce arch-length deficiency, C. To plan for extensive appliance therapy, D. To reduce arch-length deficiency & to plan for extensive appliance therapy', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Benefits of Serial Extraction \n\nSerial extraction guides or encourages eruption of permanent teeth in a favorable position.\nReduces malposition of individual teeth.\nAvoids loss of labial alveolar bone.\nReduces treatment time when active orthodontic treatment is required.\xa0\n\nTextbook of ORTHODONTICS Sridhar Premkumar', 'role': 'assistant'}]