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 one of the following is not true about ultra sonics \nSelect and explain. \nA. Oscillates between 1500 to 3000 Hz, B. Releases energy known as cavitation, C. Acoustic streaming, D. Implosion', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]