This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Miscellaneous, Subject name: Surgery
[{'content': 'Nitrogen washout curve is used in \nSelect and explain. \nA. Vital capacity, B. Inspiratory reserve volume, C. Functional residual capacity, D. Residual volume', 'role': 'user'}, {'content': 'Answer: C \nExplanation: C. i.e. (Functional residual capacity) (62- 63 Anesthesia - Janes - Duke 3rd)Functional residual capacity (RV + ERV)* Measuring FRC is the cornerstone for determining the remainder of the lung volumesThree different technique1. Helium equilibration /dilution2. Nitrogen wash out3. Body plethysmography* Plethysmography is most accurate for determining FRC in patients with COPD and applies Boyles law', 'role': 'assistant'}]