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
Direct Fick method of measuring cardiac output requires estimation of: 
Select and explain. 
A. 02 content of aerial blood, B. 02 consumption per unit time, C. 02 content of blood from right ventricle, D. All of the above
D: All of the above
Answer: D: All of the above 
Explanation: All of the above