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: Anatomy
In an emphysema patient with bullous lesions, which is the investigation to measure lung volume 
Select and explain. 
A. Body plethysmography, B. Gas dilation, C. Transdiaphragmatic pressure, D. DLCO
A: Body plethysmography
Answer: A: Body plethysmography 
Explanation: Body plethysmography is the investigation of choice for estimating lung volumes in the settings of COPD with bullous lesions ( traped air) Ref Harrison 19th edition pg 306e_6