A nurse is caring for a group of clients on a medical surgical unit. Which of the following clients is at greatest risk for urinary retention?

The client who was treated with antibiotics for a staphylococcal infection of the skin 2 weeks ago.

The client who reported eating a diet high in calcium oxalate.

The client who had general anesthesia for back surgery 4 hr ago.

The client who has a history of liver failure.