You have an Azure DNS zone named adatum.com. You need to delegate a subdomain named research.adatum.com to a different DNS server in Azure. What should you do?
A. Create an PTR record named research in the adatum.com zone.
B. Create an NS record named research in the adatum.com zone.
C. Modify the SOA record of adatum.com.
D. Create an A record named ".research in the adatum.com zone.
