A nurse in an emergency department is receiving report for four clients. Which of the following clients should the nurse see first?

Rationale: A. A client who reports frequent and painful urination: This client likely has a urinary tract infection, which requires assessment and treatment but is not immediately life-threatening. B. A client who reports left arm pain following a fall: Pain from trauma requires evaluation, but unless there are signs of impaired circulation or severe injury, it is lower priority than potential neurologic emergencies. C. A client who has hypertension and reports a severe headache: A severe headache in a client with hypertension may indicate a hypertensive crisis or impending stroke. Immediate assessment is required to prevent life-threatening complications, making this the highest priority. D. A client who has heart failure and received a diuretic 30 min ago: Monitoring is necessary to assess diuretic effects, but this client is stable and does not require immediate intervention compared with the client at risk for hypertensive emergency.