<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 6-year-old boy and his parents present to the emergency department with high-grade fever, headache, and projectile vomiting. The boy was born at 39 weeks gestation via spontaneous vaginal delivery. He is up to date on all vaccines and is meeting all developmental milestones. Past medical history is noncontributory. He has had no sick contacts at school or at home. The family has not traveled out of the area recently. He likes school and playing videogames with his younger brother. Today, his blood pressure is 11576 mm Hg, heart rate is 110min, respiratory rate is 22min, and temperature is 38.4C 101.2F. On physical exam, the child is disoriented. Kernigs sign is positive. A head CT was performed followed by a lumbar puncture. Several aliquots of CSF were distributed throughout the lab. Cytology showed high counts of polymorphs, biochemistry showed low glucose and elevated protein levels, and a gram smear shows gram-positive lanceolate-shaped cocci alone and in pairs. A smear is prepared on blood agar in an aerobic environment and grows mucoid colonies with clearly defined edges and alpha hemolysis. On later evaluation they develop a draughtsman appearance. Which one of the following is the most likely pathogen?? A: Streptococcus pneumoniae, B: Streptococcus agalactiae, C: Staphylococcus epidermidis, D: Staphylococcus aureus, E: Neisseria meningitidis,  <response>: This is a clinical vignette describing a 6-year-old boy presenting with signs and symptoms of meningitis, including high-grade fever, headache, vomiting, disorientation, and positive Kernigs sign. Diagnostic tests reveal CSF findings consistent with bacterial meningitis, including high polymorphonuclear leukocyte count, low glucose, and high protein. Gram stain of CSF shows gram-positive cocci in pairs, and culture grows alpha-hemolytic streptococci with a characteristic draughtsman colony morphology. Based on the clinical presentation and diagnostic findings, the most likely pathogen is Streptococcus pneumoniae. S. pneumoniae is a common cause of bacterial meningitis in children. It is gram-positive cocci that appears in pairs on Gram stain. It grows as mucoid colonies with alpha hemolysis on blood agar. The description of the distinctive draughtsman colony morphology helps confirm the identification as S. pneumoniae.The other options can be ruled out: S. agalactiae is a cause of neonatal meningitis but not a common pathogen in this age group. S. epidermidis and S. aureus are gram-positive cocci but not typical causes of meningitis with this presentation. N. meningitidis is a gram-negative diplococcus that causes meningitis but does not match the gram stain or culture findings here.A: Streptococcus pneumoniae 