This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: ABG Analysis Simplified, Subject name: Medicine
In chronic respiratory alkalosis, HCO3- falls by _____ mmol/L for every 10 mm Hg decrease in C02 
Select and explain. 
A. 1, B. 2, C. 3, D. 4
D: 4
Answer: D: 4 
Explanation: R. acidosis: CO2| HCO3| Compensation Acute 10 mm 1 meq Chronic 10 mm 4 meq R. alkalosis CO2| HCO3| Acute 10mm 2meq Chronic 10mm 4meq