This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Blood, Subject name: Pathology
Antithrombin is protein produced by 
Select and explain. 
A. Liver, B. Spleen, C. Kidney, D. Lung
A: Liver
Answer: A: Liver 
Explanation: (Liver): (459- 992 H 18th edition)ANTI THROMBIN (or anti thrombin III) is the major plasma protease inhibitor of thrombin and the other clotting factors in coagulation. Synthesized in the liver and circulating in plasma at a concentration of 2.6 + 0.4mm antithrombin acts as suicide substrate for its target enzymes.