The correct option is
C Heparin
Heparin is an anticoagulant as they prevents the clotting of the blood. It inactivates the thrombin in the clotting process. It is produced by the basophils and mast cells. It binds to the enzyme inhibitor antithrombin III (ATIII). The activated AT then inactivates thrombin, factor Xa and other proteases responsible for clotting of blood. It is synthesized in the liver and circulates in plasma. It is a glycosaminoglycan.
So, the correct answer is option C.