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
At which stage of Nolla's, the tooth starts erupting? 
Select and explain. 
A. Stage 5, B. Stage 6, C. Stage 7, D. Stage 8
B: Stage 6
Answer: B: Stage 6 
Explanation: None