https://cloud.google.com/nat/docs/overview

Once you have the exported file from your other provider, you can use the gcloud dns record-sets import command to import it into your managed zone.
To import record-sets, you use the dns record-sets import command. The --zone-file-format flag tells importto expect a BIND zone formatted file. If you omit this flag, import expects a YAML-formatted records file.
Reference: https://medium.com/@prashantapaudel/gcp-certification-series-2-4-planning-and-configuring- network-resources-8045ac2cc2ac

Option B is the Correct choice because, On organization Datachamps add admin-bigquery to the predefined role bigquery.admin this provides permissions to manage all resources across the project and manage all data across the project, and can cancel jobs from other users running across the project.. Add Monitorbigquery to the predefined role bigquery.dataViewer ,when applied at the project or organization level, this role can also enumerate all datasets in the project and this the appropriate role to fulfil the objective of monitoring tables across all projects .