You have an Azure Active Directory (Azure AD) tenant that syncs to an Active Directory forest. The tenant-uses through authentication.
A corporate security policy states the following:
✑ Domain controllers must never communicate directly to the internet.
✑ Only required software must be- installed on servers.
The Active Directory domain contains the on-premises servers shown in the following table.
You need to ensure that users can authenticate to Azure AD if a server fails.
On which server should you install an additional pass-through authentication agent?
A . Server2
B . Server4
C . Server1
D . Server3
Answer: C