Final answer:
A priority nursing responsibility when caring for a 4-year-old child postoperatively after genitourinary surgery would be to provide age-appropriate toys such as tricycles.
Step-by-step explanation:
A priority nursing responsibility when caring for a 4-year-old child postoperatively after genitourinary surgery would be to provide age-appropriate toys such as tricycles. This is because allowing the child to engage in play and physical activity can support their growth and development, promote healing, and help distract them from any discomfort or anxiety related to the surgery. It is important to choose toys that are safe and suitable for their age and developmental stage.