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: Ophthalmology
Normal IOP is range is ____________ 
Select and explain. 
A. 10 - 15 mmHg, B. 5 - 10 mmHg, C. 11 - 21 mmHg, D. 9 - 25 mmHg
C: 11 - 21 mmHg
Answer: C: 11 - 21 mmHg 
Explanation: None