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
An impoant non-respiratory function of lungs is 
Select and explain. 
A. Anion balance, B. Defence against inhaled air, C. Potassium balance, D. Calcium balance
B: Defence against inhaled air
Answer: B: Defence against inhaled air 
Explanation: These nonrespiratory functions of the lung include its own defense against inspired paiculate matter, the storage and filtration of blood for the systemic circulation, the handling of vasoactive substances in the blood, and the formation and release of substances used in the alveoli or circulation Ref: guyton and hall textbook of medical physiology 12 edition