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
Oxygen as an emergency drug is contraindicated in 
Select and explain. 
A. Anaphylaxis, B. Asthma, C. Hyperventilation, D. COPD
C: Hyperventilation
Answer: C: Hyperventilation 
Explanation: None