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': 'According to the treatment plan plaque control, root planning under: \nSelect and explain. \nA. Preliminary phase., B. Etiotropic phase., C. Surgical phase., D. Restorative phase.', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Phase 1 is also known as Etiotropic phase which includes plaque control, diet control, scaling, root planning and temporary restorations.', 'role': 'assistant'}]