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: Physiology
In the entire human genome, coding DNA constitutes? 
Select and explain. 
A. 2%, B. 1%, C. 0.10%, D. 4%
A: 2%
Answer: A: 2% 
Explanation: Ans. a. 2%