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
Calculate the minute ventilation from the spirogram assuming the respiratory rate as 12/min 
Select and explain. 
A. 1 L/min, B. 2 L/min, C. 4 L/min, D. 6 L/min
D: 6 L/min
Answer: D: 6 L/min 
Explanation: Ans. (d) 6L/min(Ref: Guyton, 13th ed.P.503)Minute ventilation = tidal volume x respiratory rateHere tidal volume is 500 ml (in the graph, it is seen as 3 L to 3.5 L)So, Minute ventilation =500x12=6L/min