A 19-year-old woman presents with lifelong menorrhagia requiring frequent transfusions and recurrent epistaxis. She reports prolonged bleeding for 3 hours after dental extraction last month. Vital signs: BP 108/72, HR 92, RR 16, Temp 37°C, SpO2 98%. Laboratory studies show platelet count 245,000/μL, PT 12 seconds, PTT 38 seconds (normal <35), fibrinogen 280 mg/dL, and normal bleeding time. She denies family history of bleeding disorders. Which of the following is the most likely explanation for her disorder?

1. A)Absence of factor XIII preventing fibrin cross linking
2. B)Deficiency of von Willebrand factor causing impaired platelet adhesion and reduced factor VIII stabilityGABARITO
3. C)Mutation in factor V causing activated protein C resistance
4. D)Defect of glycoprotein IIb IIIa causing impaired platelet aggregation
5. E)Autoantibody to ADAMTS13