What can be the non-respiratory functions of lungs:: (A) Sodium balance., (B) Fibrinolytic function., (C) Secretion of heparin., (D) All of the above.
Answer is D. NON respiratory function of lung: 

ACE synthesized by lung – Na balance. 
Fibrinolytic function – Pulmonary Endothelium is rich in PLASMIN activator. 
Heparin – Lung is rich in mast cells which secrete heparin. 
SURFACTANT – Synthesized by type 2 alveolar epithelial cells.