A client with renal calculi is experiencing hematuria and reports severe flank pain. Which intervention should the nurse implement first?

Choice A reason: Preparing the client for a CT scan is important for diagnostic purposes but is not the immediate priority in managing severe pain.Choice B reason: Straining the urine for stones is important for confirming the presence of renal calculi but should be done after managing the acute pain.Choice C reason: Obtaining a urine specimen for analysis is useful for diagnosing infection or other abnormalities but is secondary to pain management.Choice D reason: Administering a prescribed opioid analgesic is the first priority to relieve the client's severe pain and provide comfort.