A nurse finds a 3-year-old child unresponsive and not breathing. The nurse begins CPR while a bystander calls EMS (emergency medical services). Another person trained in CPR arrives. What is the next appropriate action?

Change to 15 compressions and 2 ventilations when the second rescuer arrives.

Send the second rescuer to get an AED.

Continue 30 compressions and 2 ventilations. Trade between the two rescuers when one gets tired.

Have the second rescuer observe the quality of CPR and offer corrections as needed.