Which of the following events during an action potential contribute to membrane potential repolarization (e. g., the falling phase of the action potential)? choose all of the correct answers. opening of the inactivation gate of the voltage-gated sodium channels closing of the inactivation gate of the voltage-gated sodium channels opening of the activation gate of the voltage-gated sodium channels closing of the activation gate of the voltage-gated sodium channels opening of the activation gate of the voltage-gated potassium channels closing of the activation gate of the voltage-gated potassium channels