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
Functional Residual volume can be measured by all except 
Select and explain. 
A. Helium dilution method, B. Spirometer, C. N2 washout method, D. Body plethysmography
B: Spirometer
Answer: B: Spirometer 
Explanation: All volume & capacities are measured by spirometer, except RV, CV, FRC & TLC which are measured by
a) N2 Washout method
b) Helium dilution method
c) Body Plethysmoglaphy (Best method)