What are two possible ways to achieve this goal?

Your company network includes two branch offices. Users at the company access internal virtual machines (VMs). You want to ensure secure communications between the branch offices and the internal VMs and network.

You need to create a site-to-site VPN connection.

What are two possible ways to achieve this goal? Each correct answer presents a complete solution
A . a private IPv4 IP address and a compatible VPN device
B . a private IPv4 IP address and a RRAS running on Windows Server 2012
C . a public-facing IPv4 IP address and a compatible VPN device
D . a public-facing IPv4 IP address and a RRAS running on Windows Server 2012

Answer: C,D

Explanation:

You must have an externally facing IPv4 IP address and a VPN device or RRAS to configure a site-to-site VPN connection.

Explanation: https://docs.microsoft.com/en-us/azure/vpn-gateway/vpn-gateway-vpn-faq