A nurse is providing education to a client about renal calculi. The client asks, "What are renal calculi?" What is the nurse's best response?

A. Citrus fruits are generally not a concern for calcium oxalate stones. They are a good source of citrate, which may actually help prevent stone formation.

B. Dairy products are not specifically associated with calcium oxalate stones. However, high-calcium supplements might increase the risk, not dietary calcium from dairy products.

C. Red meat is not a significant concern for calcium oxalate stones. It is more associated with uric acid stones.

D. This is the correct answer. Leafy green vegetables are high in oxalates, which can contribute to calcium oxalate stone formation. Clients with calcium oxalate stones should limit their intake of these vegetables.

A. Uric acid stones may cause pain, but they do not typically present with costovertebral angle tenderness. Uric acid stones are more likely to be associated with gout and hyperuricemia.

B. Calcium oxalate stones are common and can cause pain, but they do not typically cause costovertebral angle tenderness. They are more likely to cause localized pain in the back or side.

C. This is the correct answer. Struvite stones, also known as infection stones, can cause severe pain that radiates to the back and lower abdomen. They are often associated with urinary tract infections, and the presence of an infection can lead to costovertebral angle tenderness.

D. Cystine stones are rare and are more likely to cause chronic, dull pain rather than sudden and severe pain with tenderness.