This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Hematology, Subject name: Pharmacology
Heparin acts as an anticoagulant by:- 
Select and explain. 
A. Activating antithrombin III, B. Inactivating antithrombin III, C. Activating thrombin, D. Activating factor Xa
A: Activating antithrombin III
Answer: A: Activating antithrombin III 
Explanation: Heparin acts an anticoagulant by activating antithrombin III and thus inactivating thrombin and factor Xa. Heparin displaces lipoprotein lipase enzyme from the endothelial wall. Other glycosaminoglycans uses are: Danaparoid is an anticoagulant.