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
The "Pulse oximetry" used in the determination of: 
Select and explain. 
A. Rate of flow, B. Oxygen saturation, C. Blood volume, D. Blood coefficient
B: Oxygen saturation
Answer: B: Oxygen saturation 
Explanation: None