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
Where are the dentists feet during any procedure when four handed dentistry is practiced 
Select and explain. 
A. On the stool support rim, B. On the floor, C. On the dental chair base, D. Where ever is convenient
B: On the floor
Answer: B: On the floor 
Explanation: None