<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 3-year-old boy is brought to the physician for evaluation of pallor and increasing lethargy for 3 days. Six days ago, he experienced abdominal pain, vomiting, and bloody diarrhea that have since resolved. The family returned from a road trip to Mexico 4-weeks ago. His temperature is 38.8C 101.8F, pulse is 128min, respirations are 30min, and blood pressure is 9660 mm Hg. Examination shows pale conjunctivae and scleral icterus. The abdomen is soft, nontender, and nondistended. Bowel sounds are hyperactive. Laboratory studies show:Hemoglobin 7.8 gdLMean corpuscular volume 92 μm3Leukocyte count 18,500mm3Platelet count 45,000mm3Prothrombin time 12 secPartial thromboplastin time 34 secSerumUrea nitrogen 32 mgdLCreatinine 1.8 mgdLBilirubinTotal 2.0 mgdLDirect 0.1 mgdLLactate dehydrogenase 1685 ULA peripheral blood smear shows schistocytes. Which of the following is the most likely mechanism of this patients presentation?? A: Bacteremia, B: IgA Immune complex-mediated vasculitis, C: Microthrombi formation, D: Deficiency of ADAMTS13, E: Infection with an RNA picornavirus,  <response>: This is a clinical case scenario describing a 3-year-old boy with pallor, lethargy, history of bloody diarrhea, fever, tachycardia, tachypnea, and laboratory findings of anemia, thrombocytopenia, elevated LDH, schistocytes on peripheral smear, and renal dysfunction. The key findings are anemia, thrombocytopenia, elevated LDH, presence of schistocytes, and renal dysfunction following a diarrheal illness. This presentation is most consistent with thrombotic microangiopathy TMA. The differential diagnosis for TMA includes:- Shiga toxin-mediated hemolytic uremic syndrome STEC-HUS: Most likely given the bloody diarrhea and recent travel to Mexico where STEC is more common. Shiga toxin leads to endothelial damage and microthrombi formation.- Disseminated intravascular coagulation DIC: Less likely given normal PT, PTT and no overt DIC. - Thrombotic thrombocytopenic purpura TTP: Less likely given the diarrhea prodrome, normal platelet count over 30K, and age under 5 years old. TTP is mediated by ADAMTS13 deficiency.- Atypical HUS: Unlikely given the preceding diarrhea illness. Atypical HUS involves alternative complement pathway dysregulation.Based on the analysis, choice C of Microthrombi formation is the most likely mechanism underlying this clinical presentation.C: Microthrombi formation 