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
A dental instrument which creates aerosols containing large number of microorganisms is the: 
Select and explain. 
A. Evacuator, B. Ultrasonic scaler, C. Amalgam condenser, D. Endodontic reamer
B: Ultrasonic scaler
Answer: B: Ultrasonic scaler 
Explanation: None