A nurse is assessing a client prior to the administration of morphine. The nurse should recognize that which of the following assessments is the priority?

A. Pupil reaction may be affected by opioids (e.g., miosis), but it is not the priority before administration. B. Urine output is important for overall monitoring, but not critical prior to a dose of morphine. C. Bowel sounds are relevant due to the risk of constipation, but this is a long-term concern, not an immediate priority. D. Respiratory rate is the priority assessment because morphine can cause respiratory depression. Ensuring the client has an adequate respiratory rate is essential before administering the medication.