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 method to evaluate bone defect is \nSelect and explain. \nA. Sounding, B. IOPA, C. Bitewing radiograph, D. Use of florid probes', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Transgingival probing is known as sounding.', 'role': 'assistant'}]