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
Indirect retainers in bilateral distal extension base removable partial dentures are based on: 
Select and explain. 
A. Class I lever principle, B. Class II lever principle, C. Class III lever principle, D. Combination of more than one of the above
B: Class II lever principle
Answer: B: Class II lever principle 
Explanation: None