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
[{'content': 'In an emphysema patient with bullous lesions, which is the investigation to measure lung volume \nSelect and explain. \nA. Body plethysmography, B. Gas dilation, C. Transdiaphragmatic pressure, D. DLCO', 'role': 'user'}, {'content': 'Answer: A \nExplanation: 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', 'role': 'assistant'}]