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: Radiology
Radiation exposure in an IOPA radiograph is ? 
Select and explain. 
A. 200 micro Sieverts, B. 26 micro Sieverts, C. 5000 micro Sieverts, D. 5 micro Sieverts
D: 5 micro Sieverts
Answer: D: 5 micro Sieverts 
Explanation: None