A nurse is caring for an infant who is dehydrated and requires IV therapy. The nurse should monitor the infant's response to therapy by performing which of the following actions?

Rationale: A. Counting wet diapers provides general insight into fluid output, but it is not the most accurate measure of overall fluid status. B. Measuring head circumference is useful for assessing neurological changes or growth, not hydration. C. Daily weight is the most accurate and sensitive indicator of fluid balance in infants, especially when performed consistently. D. Vital signs can reflect dehydration, but they are less reliable than daily weight for ongoing monitoring of rehydration progress.