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': 'A non-invasive way of evaluating implant stability by impact resistance \nSelect and explain. \nA. Periotest, B. Transgingival probing, C. Bone sounding, D. Probing', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]