A patient has been diagnosed with a urinary tract infection. From the antibiotics below which is the most appropriate?

A. Vancomycin: Vancomycin is primarily used to treat serious gram-positive infections, such as MRSA or Clostridioides difficile. It is not a first-line treatment for uncomplicated urinary tract infections and is reserved for severe, resistant infections. B. Erythromycin: Erythromycin has limited activity against common urinary pathogens such as Escherichia coli. It does not achieve adequate concentrations in the urinary tract, making it an inappropriate choice for treating UTIs. C. Nitrofurantoin: Nitrofurantoin is commonly prescribed for uncomplicated urinary tract infections because it concentrates in the urine and is highly effective against typical UTI causing organisms. It is considered a first-line therapy for acute uncomplicated cystitis. D. Tetracycline: Tetracycline is not commonly used for UTIs due to widespread bacterial resistance and less reliable urinary concentrations. Safer and more effective alternatives, such as nitrofurantoin, are preferred.