A nurse is caring for a 4-year-old who was admitted with acute diarrhea and dehydration. Which finding indicates that oral rehydration therapy has been effective?

A. A capillary refill greater than 3 seconds suggests ongoing dehydration and poor perfusion, indicating that oral rehydration has not been fully effective. B. A respiratory rate of 24/min is within normal limits for a 4-year-old but is not a direct indicator of hydration status. C. A urine specific gravity of 1.015 is within the normal range, indicating adequate hydration and that oral rehydration therapy has been effective. D. A heart rate of 130 bpm, while potentially normal for a 4-year-old, does not specifically indicate the effectiveness of rehydration therapy.