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
peak expiratory flow: 
Select and explain. 
A. 400-600 l/min, B. 1200 L/min, C. Both, D. None
A: 400-600 l/min
Answer: A: 400-600 l/min 
Explanation: Peak expiratory flow: it is maximum velocity in L per minute with which air is forced out of lung Ref: G K Pal Textbook of Practical Physiology 4th edition, page number:159