A nurse is caring for a client who reports recurrent flank pain, nausea, and vomiting for 24 hr. Which of the following actions is the nurse's priority?

A. Administering an antiemetic can provide relief, but it is not the first priority in this case. B. Administering pain medication is the priority because managing acute pain is essential for client comfort and can reduce stress responses. C. Straining the urine is important for identifying possible kidney stones but is not the most immediate concern. D. Monitoring intake and output helps assess kidney function but is secondary to relieving severe pain.