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': 'In guided tissue regeneration technique for root coverage, the titanium-reinforced membrane was used\nby___________ to create space beneath the membrane. \nSelect and explain. \nA. Tinti and Vincenzi, B. Pini-Prato and Tonetti, C. Ramfjord and Nissle, D. Widman and Cohen', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]