The best practice recommended by Google for accessing multiple GKE clusters is to use the gcloud container clusters get-credentials command. This command automatically retrieves the credentials for the specified cluster and updates the local kubeconfig file with the correct context, user, and cluster information. Option C ensures developers install the gcloud CLI locally, allowing them to use their preferred workstation tools while securely managing authentication via IAM. Options A and B are less ideal: Cloud Shell (A) limits local tool usage, and manually sharing config files (B) bypasses secure credential handling. Option D is impractical for managing multiple clusters.