Your network contains an internal network and a perimeter network. The internal network contains an Active Directory forest. The forest contains a single domain. 
You plan to deploy 10 Edge Transport servers on the perimeter network. 
You need to recommend a solution for the Edge Transport server deployment. The solution must meet the following requirements：
.Allow administrators to apply a single security policy to all Edge Transport servers
.Reduce the administrative overhead that is required to manage servers
.Minimize the attack surface of the internal network
What should you recommend？（）

A.Implement Network Policy and Access Services （NPAS）.
B.Implement Active Directory Federation Services （AD FS）.
C.Create a new Active Directory domain in the internal forest， and then join all Edge Transport servers to the new domain.
D.Create an Active Directory forest in the perimeter network， and then join all Edge Transport servers to the new domain.