A nurse is assessing a client 15 min after administering morphine sulfate 2 mg via IV push. The nurse should identify which of the following findings as an adverse effect of the medication?

Rationale: A. Pain level of 6 on a scale from 0 to 10 indicates inadequate pain relief, not an adverse effect of morphine. B. While slightly lower than normal, this oxygen saturation does not indicate a serious adverse effect by itself. C. Respiratory depression is the most serious adverse effect of morphine. A rate below 12/min is concerning and requires immediate intervention. D. This indicates expected sedation from morphine, not a dangerous adverse effect unless accompanied by severe unresponsiveness or very low respirations.