A 6-week-old infant with pyloric stenosis is scheduled for a pyloromyotomy. Which pre- operative nursing action has the highest priority?

A. Marking the outline of the "olive-shaped" mass is important for diagnosis but is not the highest priority in pre-operative care. B. Instructing parents regarding care of the incisional area is important but not the highest priority before surgery. C. Monitoring feedings is important, but the primary concern is ensuring hydration and electrolyte balance, which may be compromised due to vomiting in pyloric stenosis. D. IV fluids are essential to correct dehydration and electrolyte imbalances caused by vomiting in pyloric stenosis. This is the highest priority to stabilize the infant before surgery.