<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 42-year-old man with hypertension and type 2 diabetes mellitus is admitted to the hospital because of swelling and redness of the left leg for 3 days. He has chills and malaise. He is treated with intravenous clindamycin for 7 days. On the 8th day at the hospital, he has profuse, foul-smelling, and watery diarrhea. He has nausea and intermittent abdominal cramping. His temperature is 38C 100.4F, pulse is 97min, and blood pressure is 11078 mm Hg. Bowel sounds are hyperactive. Abdominal examination shows mild tenderness in the left lower quadrant. Rectal examination shows no abnormalities. His hemoglobin concentration is 14.3 gdL, leukocyte count is 12,300mm3, and C-reactive protein concentration is 62 mgL N0.083.1. After discontinuing clindamycin, which of the following is the most appropriate pharmacotherapy for this patients condition?? A: Oral metronidazole, B: Intravenous vancomycin, C: Oral fidaxomicin, D: Oral rifaximin, E: Intravenous metronidazole,  <response>: This is a question about treating Clostridioides difficile infection CDI. The patient has several risk factors for CDI including recent hospitalization, antibiotics clindamycin use, and older age. His symptoms of watery diarrhea, abdominal pain, fever, and leukocytosis are classic for CDI. The choices include oral metronidazole, intravenous vancomycin, oral fidaxomicin, oral rifaximin, and intravenous metronidazole. Based on guidelines, oral vancomycin or fidaxomicin are preferred over metronidazole for initial episodes of CDI. Rifaximin lacks activity against C. difficile and would not be appropriate. Intravenous vancomycin could be used for severe CDI, but this patient has mild-moderate disease based on the clinical description.C: Oral fidaxomicin 