Server1 hosts a primary DNS zone adatum.com with ~1,000 records. You manage Server1 and Subscription1 from Server2, which has DNS Manager, Azure PowerShell, and Azure CLI 2.0 installed. To move the adatum.com zone into an Azure DNS zone in Subscription1 with minimal administrative effort, which tool should you use?

Azure CLI is the most efficient tool for migrating an existing DNS zone to Azure DNS with minimal administrative effort. It offers a direct command, az network dns zone import, which can import a BIND-formatted DNS zone file. This command automatically parses the zone file and creates all corresponding records in the Azure DNS zone, streamlining the migration process for a large number of records like the 1,000 in adatum.com. Azure PowerShell also has cmdlets for DNS management, but it lacks a single, direct import command comparable to the Azure CLI's az network dns zone import. You would typically need to parse the zone file and create records individually or with a custom script, requiring more effort. The Azure portal is not suitable for importing an entire zone file; it requires manual entry of each record, which would be time-consuming for 1,000 records. The DNS Manager console is for managing on-premises DNS servers and cannot directly interact with or migrate zones to Azure DNS.