You administer two Windows Server 2012 R2 servers that have the Hyper-V role installed. You use System
Center 2012 Virtual Machine Manager (VMM) to manage the Hyper-V host servers.You need to create a server lab environment.
The lab servers have the following requirements:
All of the lab servers must be virtualized. All of the lab servers must be on an isolated network.
All of the lab servers must be able to communicate with each other.
You need to configure networking for the lab environment.
What should you do?

A.
Create a logical switch.

B.
Create a media access control (MAC) pool.

C.
Add a load balancer.

D.
Create a private virtual LAN (PVLAN) logical network.

Explanation:
https://blogs.technet.microsoft.com/scvmm/2013/06/04/logical-networks-part-iv-pvlan-isolation/