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
Among which hypoxia AV 0 difference is max ? 
Select and explain. 
A. Histotoxic, B. Stagnant, C. Hypoxic, D. Anemic
B: Stagnant
Answer: B: Stagnant 
Explanation: Ans. is 'b' i.e., Stagnant