<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 15-year-old man presents with his father to the urgent care department with a 5-day history of frequent diarrhea, occasionally mixed with streaks of blood. Stool cultures are pending, but preliminary stool samples demonstrate fecal leukocytes and erythrocytes. The patients vital signs are within normal limits, and he is started on outpatient therapy for presumed Shigella infection. Which of the following was the young man most likely started on?? A: Oral erythromycin, B: Oral metronidazole, C: Oral vancomycin, D: An oral quinolone, E: Oral trimethoprim-sulfamethoxazole TMP-SMX,  <response>: This is a clinical case of a 15-year-old male presenting with diarrhea mixed with blood for 5 days. Stool studies show leukocytes and red blood cells, indicating inflammation and bleeding in the colon. The most likely diagnosis based on the clinical presentation is infectious colitis, with Shigella being the presumed organism. Shigella is a gram-negative bacteria that causes inflammatory diarrhea and dysentery. The treatment of choice for Shigella colitis is an antibiotic that covers gram-negative organisms.E: Oral trimethoprim-sulfamethoxazole TMP-SMX 