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': 'Best position for apically displaced flap is \nSelect and explain. \nA. At the alveolar crest, B. At 2mm apical to alveolar crest, C. At 1mm apical to alveolar crest, D. At 1mm coronal to alveolar crest', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]