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
The kind of hypoxia seen in the collapse of lungs and depression of respiratory centre is: 
Select and explain. 
A. Hypoxic hypoxia., B. Anaemic hypoxia., C. Stagnant hypoxia., D. Histotoxic hypoxia.
A: Hypoxic hypoxia.
Answer: A: Hypoxic hypoxia. 
Explanation: In this condition oxygen therapy is useful.