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 enamel rods has been estimated in lower incisors as 
Select and explain. 
A. 5 million, B. 10 million, C. 2 million, D. 12 million
A: 5 million
Answer: A: 5 million 
Explanation: None