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: Unknown
[{'content': 'Thrombosthenin is: \nSelect and explain. \nA. Coagulation factor, B. Contractile protein, C. A thrombosis promoting protein, D. A protein regulating platelet production', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Thrombosthenin, platelet contractile proteins contract and help in clot retraction 48 hours after injury. the\xa0contractile\xa0protein\xa0of\xa0platelets is,\xa0responsible\xa0for\xa0clot\xa0retraction , platelet\xa0aggregation,\xa0and\xa0release\xa0of ADP\xa0and\xa0other\xa0biologic\xa0amines\xa0essential\xa0to\xa0platelet\xa0function.', 'role': 'assistant'}]