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': 'Which of the following has greatest impact on success of\na periodontal flap procedure? \nSelect and explain. \nA. Level of postoperative plaque control, B. Level of flap at closure, C. Extent to which flap is reflected, D. Type of incision', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]