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
[{'content': 'Heparin acts activation of: \nSelect and explain. \nA. Antithrombin III, B. Factor VIII, C. Factor II and X, D. Factor V', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Heparin activates plasma anti thrombin III. Anti thrombin binds to and inhibits the activated thrombin and coagulation factors ( Xa and IXa). From medical pharmacology padmaja 4th edition Page no 334', 'role': 'assistant'}]