Final answer:
The nurse's understanding of age-appropriate distraction interventions can be seen in using a stuffed animal for an infant. So, the correct answer is option 4: D. Using a stuffed animal for an infant.
Step-by-step explanation:
The nurse's understanding of age-appropriate distraction interventions can be seen in option D, which is using a stuffed animal for an infant.
Offering a puzzle for a toddler (option A) may not be appropriate because toddlers have not yet developed the fine motor skills required for puzzles. Providing a smartphone for a school-age child (option B) may not be suitable because excessive screen time can have negative effects on a child's development.
Giving a coloring book to a teenager (option C) may not be effective as teenagers typically have different interests and may find other forms of distraction more engaging.
Option 4: D. Using a stuffed animal for an infant is age-appropriate as infants are often comforted by soft toys and it helps to distract them from discomfort or pain.