The following are multiple choice questions (with answers) about medical knowledge.   **Question:** Six days after undergoing an aortic valve replacement surgery, a 68-year-old woman has bluish discolorations around the peripheral intravenous catheters and severe right leg pain. She has a history of hypertension and major depressive disorder. She drinks 3 beers daily. Current medications include hydrochlorothiazide, aspirin, prophylactic unfractionated heparin, and fluoxetine. Her temperature is 37.3°C (99.1°F), pulse is 90/min, and blood pressure is 118/92 mm Hg. Examination shows multiple hematomas on the upper extremities around the peripheral intravenous access sites. There is a healing sternal incision. The lungs are clear to auscultation. Cardiac examination shows an aortic click. The right calf is tender, erythematous and swollen. Laboratory studies show: Hemoglobin 13.1 g/dL Leukocyte count 9,900/mm3 Platelet count 48,000/mm3 Prothrombin time 15 seconds Activated partial thromboplastin time 40 seconds Serum Urea nitrogen 19 mg/dL Creatinine 1.1 mg/dL Alkaline phosphatase 33 U/L AST 26 U/L ALT 33 U/L γ-Glutamyl transferase 45 U/L (N=5–50 U/L) Which of the following is the most likely underlying mechanism of this patient's symptoms?"   (A) Deficiency of vitamin K-dependent clotting factors   (B) Phagocytosis of autoantibody-opsonized platelets   (C) Excess circulating thrombin   (D) Autoantibody-mediated platelet activation
['(D) Autoantibody-mediated platelet activation <> answer', 'The following are multiple choice questions (with answers) about medical knowledge. <> instruction', '(A) Deficiency of vitamin K-dependent clotting factors \n (B) Phagocytosis of autoantibody-opsonized platelets \n (C) Excess circulating thrombin \n (D) Autoantibody-mediated platelet activation <> possible answers', '  Six days after undergoing an aortic valve replacement surgery, a 68-year-old woman has bluish discolorations around the peripheral intravenous catheters and severe right leg pain. She has a history of hypertension and major depressive disorder. She drinks 3 beers daily. Current medications include hydrochlorothiazide, aspirin, prophylactic unfractionated heparin, and fluoxetine. Her temperature is 37.3°C (99.1°F), pulse is 90/min, and blood pressure is 118/92 mm Hg. Examination shows multiple hematomas on the upper extremities around the peripheral intravenous access sites. There is a healing sternal incision. The lungs are clear to auscultation. Cardiac examination shows an aortic click. The right calf is tender, erythematous and swollen. Laboratory studies show:\nHemoglobin 13.1 g/dL\nLeukocyte count 9,900/mm3\nPlatelet count 48,000/mm3\nProthrombin time 15 seconds\nActivated partial thromboplastin time 40 seconds\nSerum\nUrea nitrogen 19 mg/dL\nCreatinine 1.1 mg/dL\nAlkaline phosphatase 33 U/L\nAST 26 U/L\nALT 33 U/L\nγ-Glutamyl transferase 45 U/L (N=5–50 U/L)\nWhich of the following is the most likely underlying mechanism of this patient\'s symptoms?" <> context@']