A 69-year-old patient in the geriatric clinic has an annual physical examination and a complete blood count and serum electrolytes are drawn. While the physical examination was uneventful, the laboratory results show an elevated blood urea nitrogen (BUN). What action will the nurse then take

Instructing the client on collecting a 24-hour urine specimen for a more detailed analysis.

Asking that the test be rerun since the client showed no physical signs of renal failure.

Reviewing the client's medication list since renal health can be affected by many specific medications.

Assuring the client that an elevated BUN is normal in older adults.