This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Blood Physiology, Subject name: Physiology
[{'content': 'Which of the following would best explain a prolonged bleeding time test? \nSelect and explain. \nA. Hemophilia A, B. Hemophilia B, C. Thrombocytopenia, D. Coumadin use', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Three major tests are used to determine coagulation defects. PT(Prothrombin time)- is used to test the extrinsic pathway aPTT(Activated Paial Thromboplastin Time)-is used to test the intrinsic pathway BT(Bleeding time)- after a small cut is used to test for several clotting factors but is especially prolonged by a lack of platelets (Thrombocytopenia).', 'role': 'assistant'}]