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: Pathology
[{'content': 'Fibrin is degraded by \nSelect and explain. \nA. Plasminogen, B. Plasmin, C. Thromboplastin, D. FD', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Clotting also sets into motion a fibrinolytic cascade that moderates\xa0the ultimate size of the clot. Fibrinolysis is largely\xa0carried out by plasmin, which breaks down fibrin and interferes\xa0with its polymerization. The resulting\xa0fibrin split products (FSPs or fibrin degradation products) also\xa0can act as weak anticoagulants.\nElevated levels of FSPs\xa0(most notably fibrin-derived D-dimers) can be used for\xa0diagnosing abnormal thrombotic states including disseminated\xa0intravascular coagulation (DIC), deep\xa0venous thrombosis, or pulmonary thromboembolism.\nPlasmin is generated by proteolysis of plasminogen, an\xa0inactive plasma precursor, either by factor XII or by plasminogen\xa0activators. The most important of the\xa0plasminogen activators is tissue-type plasminogen activator\xa0(t-PA); t-PA is synthesized principally by endothelial cells\xa0and is most active when attached to fibrin.', 'role': 'assistant'}]