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: Physiology
The volume in lungs at the time of full relaxation of lungs is 
Select and explain. 
A. FRC, B. Tidal volume, C. Inspiratory reserve volume, D. Expiratory reserve volume
A: FRC
Answer: A: FRC 
Explanation: Functional residual capacity: Amount of air remaining in the lungs after a normal tidal expiration (RV + ERV). Around 2400 mlRef: Ganong review of medical physiology 23rd edition Page no: 593