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
Ferrier double bow separator works on which principle? 
Select and explain. 
A. Wedge principle, B. Traction principle, C. Slow separation, D. Delayed tooth movement
B: Traction principle
Answer: B: Traction principle 
Explanation: The Ferrier separator is a convenient instrument for accomplishing separation. It is applied and stabilized with compound. The jackscrews of the separator are activated with the separator wrench to draw the teeth slightly apart, creating a maximum space of 0.25 to 0.5 mm. It is desirable to provide only this minimum separation and to remove the separator as soon as possible.
Sturdevants operative dentistry 7th edition page e85 - e86