A 47-year-old hospitalized patient with watery diarrhea after 7 days of antibiotics has WBC 12,000/μL, creatinine normal, and positive NAAT for toxin genes with toxin EIA positive. What is preferred initial therapy?AOral metronidazole 500 mg TID for 10 daysBOral vancomycin 125 mg QID for 10 days or fidaxomicin 200 mg BID for 10 days, with fidaxomicin preferredCStop antibiotics only; no specific therapy neededDProbiotics as sole therapyEIV vancomycinCheck my answer