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
According to Ellis and Deway classification, displacement of tooth without fracture if crown or root is: 
Select and explain. 
A. Class 6, B. Class 7, C. Class 8, D. None
B: Class 7
Answer: B: Class 7 
Explanation: None