This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Respiratory system, Subject name: Physiology
Which of the following is the best determinant of adequacy of alveolar ventilation? 
Select and explain. 
A. Aerial pO2 level, B. Aerial pCO2 level, C. Minute ventilation, D. Presence of cyanosis
B: Aerial pCO2 level
Answer: B: Aerial pCO2 level 
Explanation: Atrial pco2 content determines the alveolar ventilation Ref: guyton and hall textbook of medical physiology 12 edition page number:331,332,333