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
What will occur with increase in alveolar ventilation rate ? 
Select and explain. 
A. Decreased paial pressure of O2 in alveoli, B. Decreased paial pressure of CO2 in alveoli, C. Decreased CO2 diffusion from blood to alveoli, D. Decreased O2 diffusion from alveoli to blood
B: Decreased paial pressure of CO2 in alveoli
Answer: B: Decreased paial pressure of CO2 in alveoli 
Explanation: Ans. is 'b' i.e., Decreased paial pressure of CO2 in alveoliAlveolar ventilation is the amount of inspired air entering in gas-exchange areas (alveoli) per minute during quite breathing. It excludes the air which remains in dead space.