This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pharmacology
[{'content': 'Heparin, apart from releasing lipoprotein lipase in the blood exerts its anti-coagulant action by: \nSelect and explain. \nA. Binding to calcium, B. Inhibiting fibrinogen synthesis, C. Inhibiting prothrombin synthesis, D. Inhibiting thrombin synthesis', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]