You need to ensure that all of the virtual machines that connect to Switch1 are isolated from the external network and can connect to each other only

Your network contains an Active Directory domain named contoso.com. The domain contains a
member server named Server 1. Server1 runs Windows Server 2012 R2 and has the Hyper-V server
role installed.
You create an external virtual switch named Switch1. Switch1 has the following configurations:
– Connection type: External network
– Single-root I/O virtualization (SR-IOV): Enabled
Ten virtual machines connect to Switch1.
You need to ensure that all of the virtual machines that connect to Switch1 are isolated from the
external network and can connect to each other only. The solution must minimize network
downtime for the virtual machines.
What should you do?

A.
Remove Switch1 and recreate Switch1 as an internal network

B.
Change the Connection type of Switch1 to Private network

C.
Change the Connection type of Switch1 to Internal network

D.
Remove Switch1 and recreate Switch1 as a private network