What is best to do in the situation is to have the bystander call 911 while you start CPR. It is best to do it immediately to ensure that the infant is receiving circulation and oxygen.
The correct choice would be to start CPR while the bystander calls 911. This would be the best option in any situation, not only with an infant. Correct answer would be A. Have the bystander call 911 while you start CPR.
