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
[{'content': 'Functional Residual volume can be measured by all except \nSelect and explain. \nA. Helium dilution method, B. Spirometer, C. N2 washout method, D. Body plethysmography', 'role': 'user'}, {'content': 'Answer: B \nExplanation: All volume & capacities are measured by spirometer, except RV, CV, FRC & TLC which are measured by\na) N2 Washout method\nb) Helium dilution method\nc) Body Plethysmoglaphy (Best method)', 'role': 'assistant'}]