<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 3-week-old boy is brought to the pediatrician by his parents for a circumcision. The circumcision was uncomplicated; however, after a few hours, the diaper contained blood, and the bleeding has not subsided. A complete blood count was ordered, which was significant for a platelet count of 70,000mm3. On peripheral blood smear, the following was noted figure A. The prothrombin time was 12 seconds, partial thromboplastin time was 32 seconds, and bleeding time was 13 minutes. On platelet aggregation studies, there was no response with ristocetin. This result was not corrected with the addition of normal plasma. There was a normal aggregation response with the addition of ADP. Which of the following is most likely true of this patients underlying disease?? A: Decreased GpIIbIIIa, B: Adding epinephrine would not lead to platelet aggregation, C: Responsive to desmopressin, D: Decreased GpIb, E: Protein C resistance,  <response>: This is a question about a 3-week-old boy with prolonged bleeding after circumcision. The key findings are thrombocytopenia low platelet count, abnormal peripheral blood smear, prolonged bleeding time, lack of platelet aggregation with ristocetin that was not corrected with normal plasma, and normal aggregation with ADP. The prolonged bleeding time and lack of platelet aggregation indicate a platelet function defect. The normal aggregation with ADP rules out storage pool disease. The lack of correction with normal plasma indicates a defect in the platelet glycoprotein receptor GPIb or GPIIbIIIa. The peripheral blood smear shows giant platelets, which is typical for GPIb deficiency Bernard-Soulier syndrome. So the underlying disease is most likely a deficiency in GPIb.D: Decreased GpIb 