This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Assessment of Growth, Subject name: Pediatrics
At what age do first permanent teeth appear? 
Select and explain. 
A. 5 years, B. 6 years, C. 7 years, D. 8 years
B: 6 years
Answer: B: 6 years 
Explanation: ANSWER: (B) 6 yearsREF: Nelson 18th Ed Ch 8Repeat 2013 Session 2