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
Number of teeth present in the oral cavity at the age between 8-9 years: 
Select and explain. 
A. 12 teeth., B. 20 teeth., C. 24 teeth., D. 28 teeth.
C: 24 teeth.
Answer: C: 24 teeth. 
Explanation: 24 teeth are present that is 12 primary and12 permanent teeth.