This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Blood: Hemostasis and Blood Coagulation, Subject name: Physiology
Which of the following plasma proteins is not synthesized primarily in liver? 
Select and explain. 
A. Angiotensinogen, B. C-reactive protein, C. Angiotensin converting enzyme, D. Fibrinogen
C: Angiotensin converting enzyme
Answer: C: Angiotensin converting enzyme 
Explanation: Ans. (c) Angiotensin II converting enzyme* The lungs also activate one hormone; the physiologically inactive decapeptide angiotensin I is converted to the pressor, aldosterone-stimulating octapeptide angiotensin II in the pulmonary circulation. The reaction occurs in other tissues as well, but it is particularly prominent in the lungs.* Large amounts of the angiotensin-converting enzyme responsible for this activation are located on the surface of the endothelial cells of the pulmonary capillaries.