<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 3-year-old girl is brought to the emergency room because of a 5-day history of high fever and fatigue. During this time she has been crying more than usual and eating less. Her mother says that the child has also complained about pain in her arms and legs for the past 3 days. She was born at term and has been otherwise healthy. She appears ill. Her temperature is 39.5C 103.1F, pulse is 128min, and blood pressure is 9652 mm Hg. The lungs are clear to auscultation. A grade 36 systolic murmur is heard at the apex. There is mild tenderness to palpation of the left upper quadrant with no guarding or rebound. The spleen is palpated 3 cm below the left costal margin. There is no redness or swelling of the joints. Laboratory studies show:Hemoglobin 11.8 gdLLeukocyte count 16,300mm3Platelet count 220,000mm3Erythrocyte sedimentation rate 50 mmhSerumGlucose 96 mgdLCreatinine 1.7 mgdLTotal bilirubin 0.4 mgdLAST 18 ULALT 20 ULUrineProtein 2RBC casts rareRBC 10hpfWBC 12hpfWhich of the following is the most appropriate next step in management?? A: Administer intravenous vancomycin, B: Measure rheumatoid factors, C: Obtain 3 sets of blood cultures, D: Obtain a transesophageal echocardiography, E: Obtain a renal biopsy,  <response>: This is a clinical case scenario involving a 3-year-old girl with high fever, fatigue, pain in arms and legs, decreased appetite, and other symptoms over the past 5 days. She has a murmur on exam and laboratory findings consistent with anemia, leukocytosis, thrombocytosis, elevated inflammatory markers, and abnormal urinalysis. The key findings are the prolonged high fever, murmur, leukocytosis, elevated ESR, and hematuriaproteinuria, which raise suspicion for an infectious endocarditis. Blood cultures are needed to identify the causative organism. Rheumatoid factor and renal biopsy may be considered later if there is concern for rheumatologic or renal involvement but are premature at this point. Echocardiography and empiric antibiotics like vancomycin should not be started yet without positive blood cultures.Of the choices given, obtaining 3 sets of blood cultures is the most appropriate next step to identify the source of infection.C: Obtain 3 sets of blood cultures 