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 App1 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 App1 continues to function after the migration. The solution must meet the security policy.
What should you include in the recommendation?
A. Azure AD Application Proxy
B. an Azure VPN gateway
C. Azure AD Domain Services (Azure AD DS)
D. the Active Directory Domain Services role on a virtual machine