Trimethoprim and Sulfamethoxazole (Bactrim) BID for 7 Days Is Ordered

Trimethoprim and sulfamethoxazole (Bactrim) BID for 7 days is ordered for a patient who has a recurrent relapse of an Escherichia coli UTI. The nurse instructs the patient to

A) take the antibiotic for the full 7 days, even if symptoms improve in a few days.
B) return to the clinic in 3 days so that a urine culture can be done to evaluate the effectiveness of the drug.
C) increase the effectiveness of the drug by taking it with cranberry juice to acidify the urine.
D) take two of the pills a day for 5 days, and reserve the rest of the pills to take if the symptoms reappear.