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
A man connected to a body plethysmograph for estimation of FRC inspires against a closed glottis. Which of the following statements is true 
Select and explain. 
A. The pressure in both the lungs and the box increases, B. The pressure in both the lungs and the box decreases, C. The pressure in the lungs decreases, but that in the box increases, D. The pressure in the lungs increases, but that in the box decreases
C: The pressure in the lungs decreases, but that in the box increases
Answer: C: The pressure in the lungs decreases, but that in the box increases 
Explanation: During Plethysmography, the following are the changes.
-        Lungs
o   During Expiration- Volume decreases, pressure increases
o   During inspiration- Volume increases, pressure decreases
-        Chamber
o   During expiration- Volume increases, pressure decreases
o   During inspiration- Volume decreases, pressure increases