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
What is the amount of time required by erupting premolar to move through 1 mm of bone as measured on a bite-wing radiograph? 
Select and explain. 
A. 3-4 months, B. 4-5 months, C. 5-6 months, D. 6-7 months
B: 4-5 months
Answer: B: 4-5 months 
Explanation: None