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
A child has 12 permanent and 12 deciduous teeth, what is his age: 
Select and explain. 
A. 8 ½ years, B. 11 ½ years, C. 4 ½ years, D. 13 ½ years
A: 8 ½ years
Answer: A: 8 ½ years 
Explanation: None