<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 54-year-old man presents with fever, abdominal pain, nausea, and bloody diarrhea. He says that his symptoms started 36 hours ago and have not improved. Past medical history is significant for a left-leg abscess secondary to an injury he sustained from a fall 4 days ago while walking his dog. He has been taking clindamycin for this infection. In addition, he has long-standing gastroesophageal reflux disease, managed with omeprazole. His vital signs include: temperature 38.5C 101.3F, respiratory rate 19min, heart rate 90min, and blood pressure 11070 mm Hg. Which of the following is the best course of treatment for this patients most likely diagnosis?? A: Ciprofloxacin, B: Tetracycline, C: Vancomycin, D: Erythromycin, E: Trimethoprim-sulfamethoxazole,  <response>: This patient has symptoms of fever, abdominal pain, nausea, and bloody diarrhea that started 36 hours ago. His recent history is significant for a leg abscess that he has been taking clindamycin for. Clindamycin can disrupt the normal gut flora and lead to Clostridium difficile infection, which can present with fever, abdominal pain, and diarrhea. The most likely diagnosis for this patient is C. difficile colitis. C. difficile is best treated with oral vancomycin or fidaxomicin. C: Vancomycin 