The correct answer is C because enabling auto-repairing for the nodes enhances resiliency and high availability by allowing Kubernetes engine to automatically replace nodes that fail health checks. This feature is crucial for maintaining a healthy, running state of your cluster without manual intervention.

• Option A is incorrect as auto-upgrades are related to updating node versions, not ensuring node health.
• Option B is incorrect because auto-healing for managed instance groups is not applicable to Kubernetes clusters.
• Option D is incorrect as there is no auto-healing feature for nodes in Kubernetes.

For more details, refer to the GCP documentation on Kubernetes Auto-Repairing.