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
Preventive and interceptive orthodontics is no longer viable after eruption of: 
Select and explain. 
A. Permanent second molars, B. Primary second molars, C. Permanent first molar, D. Permanent lateral incisors
A: Permanent second molars
Answer: A: Permanent second molars 
Explanation: None