A nurse is preparing to administer metoprolol to a client. Which of the following vital signs should the nurse assess before administration?

A. Respiratory rate is not the primary vital sign to assess before administering metoprolol. B. Temperature is not directly affected by metoprolol and should not be assessed solely for this purpose. C. Oxygen saturation is not a vital sign directly impacted by metoprolol. D. Heart rate should be assessed before metoprolol, a beta-blocker, because it can lower heart rate. If the heart rate is below the target range, the medication should be withheld.