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
2 root canals are found in what percentage of Mandibular incisors 
Select and explain. 
A. 22-40%, B. 11-22%, C. 20-50 %, D. 5-15%
A: 22-40%
Answer: A: 22-40% 
Explanation: None