A 6-year-old boy presents to the emergency department with epistaxis and diffuse petechiae on his lower extremities and trunk. His mother reports he had an upper respiratory infection 3 weeks ago that resolved spontaneously. Physical examination reveals no fever, lymphadenopathy, or hepatosplenomegaly. Vital signs: BP 95/60, HR 115/min, RR 22/min, temperature 37.2°C, SpO2 98% on room air. Laboratory studies show platelet count 18,000/μL, hemoglobin 12.5 g/dL, WBC 7,200/μL with normal differential. Coagulation studies (PT, PTT, fibrinogen) are all normal. Bone marrow biopsy demonstrates normal to increased megakaryocytes with normal morphology and no evidence of dysplasia or infiltration. Which of the following pathophysiologic mechanisms best explains this patient's thrombocytopenia?

1. A)Antibody-mediated destruction of platelets with normal bone marrow productionGABARITO
2. B)Consumptive coagulopathy with platelet deposition in microvasculature
3. C)Decreased thrombopoietin signaling resulting in impaired megakaryopoiesis
4. D)Viral infection causing direct cytolysis of bone marrow megakaryocytes
5. E)Bone marrow aplasia secondary to post-viral immune suppression