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
The pattern of vibration of magnetostrictive type of ultrasonic scaler is 
Select and explain. 
A. Elliptical, B. Linear, C. Back and forth, D. None
A: Elliptical
Answer: A: Elliptical 
Explanation: None