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
Which of the following is seen in high attitude climbers: 
Select and explain. 
A. Hyperventilation, B. Hyperventilation, C. Pulmonary edema, D. All
D: All
Answer: D: All 
Explanation: A i.e. Hyperventilation, (B) i.e. Decreased Pa CO2 (C) pulmonary edema