The nurse is admitting a patient to the acute care floor. While obtaining the history, the client tells the nurse she is allergic to penicillin. Which of the following medications, if ordered by the physician, would be safe for this client?

A. Erythromycin (E-mycin): Erythromycin is a macrolide antibiotic, which has a different chemical structure from penicillins, making it safe for patients with penicillin allergies. B. Piperacillin-tazobactam (Zosyn): Piperacillin-tazobactam is a penicillin derivative and should be avoided in patients with penicillin allergies due to the risk of cross-reactivity. C. Ampicillin sulbactam (Unasyn): Ampicillin is a penicillin antibiotic, and therefore, should not be used in patients with penicillin allergies. D. Cefazolin (Kefzol): Cefazolin is a cephalosporin antibiotic. There is a potential for cross-reactivity in patients with penicillin allergies, especially if the allergy is severe. It may be used with caution or avoided depending on the patient's allergy history.