Your company has the infrastructure shown in the following table.

The on-premises Active Directory domain syncs to Azure Active Directory (Azure AD).
Server1 runs an application named Appl that uses LDAP queries to verify user identities in the on-premises Active Directory domain.
You plan to migrate Server1 to a virtual machine in Subscription1.
A company security policy states that the virtual machines and services deployed to Subscription1 must be prevented from accessing the on-premises network.
You need to recommend a solution to ensure that Appl continues to function after the migration. The solution must meet the security policy.
What should you include in the recommendation?
Correct Answer: A
https://docs.microsoft.com/en-us/azure/active-directory-domain-services/overview Azure Active Directory Domain Services (Azure AD DS) provides managed domain services such as domain join, group policy, lightweight directory access protocol (LDAP), and Kerberos/NTLM authentication Azure AD Domain Services (Azure AD DS) - This one could work since AAD DS will bring in the existing accounts from Azure AD which in turn are synchronised from on-premise AD over AD connect. However, you would probably need to reconfigure the app and update the LDAP connection Azure Active Directory (Azure AD) supports LDAP Authentication via Azure AD Domain Services (AD DS). https://docs.microsoft.com/en-us/azure/active-directory/fundamentals/auth-ldap
https://docs.microsoft.com/en-us/azure/active-directory-domain-services/synchronization