A new modification to the current Deployment has rendered it unstable.

If a new modification to a Deployment has rendered it unstable, then the best way to regain stability is to rollback to an earlier Deployment. Rolling back to a previous Deployment will restore the system to its previous configuration, which should restore stability. The other options are not related to this process.

References: [1] https://kubernetes.io/docs/tutorials/kubernetes-basics/update/update-intro/  [2] https://kubernetes.io/docs/reference/generated/kubectl/kubectl-commands#rollback