The correct approach involves using Docker to create a container image, pushing it to the Google Container Registry, and then deploying the image to Kubernetes using kubectl. This method ensures that your application is containerized and stored in a registry that Kubernetes can access for deployment. The kubectl apply command is used to apply configurations to resources but is not directly used to push Docker files to Kubernetes. Similarly, saving the Docker image to Cloud Storage or attempting to convert the Docker file into a deployment with kubectl convert are not standard practices for deploying applications to Kubernetes.