A child returns from a successful spinal fusion surgery. What is the top priority assessment for this child?

Rationale: A. Overhydration is not the immediate priority after spinal fusion surgery. B. Seizure activity is not commonly associated with spinal fusion surgery. C. Pupillary response assessment is more relevant to neurological or head injuries, not spinal surgery. D. Assessing color, sensitivity, and movement of the lower extremities is crucial to detect early signs of neurovascular compromise or spinal cord injury following spinal fusion. Prompt recognition can prevent permanent damage.