You are working in a Global Pharma firm, having its Head Office in Washington & Branch offices in Chicago & Paris. The Firm has a two-tier Intranet website deployed in US-East-1 Region & database servers deployed on-premise at the Head office. The Head Office has a Direct Connect link to VPC, and it is connected to Chicago & Paris offices via WAN links, while each of these offices has separate internet links from the local ISP. Recently they faced link outage issues with WAN links that resulted in the isolation of the branch offices from the head office. They are looking for a cost-effective backup solution that could be set-up quickly without any additional devices and links. What would be the most suitable connectivity option in this scenario?

Answer options:

A.Using existing Internet connection in Washington, Chicago, and Paris, set up a Direct Connection with us-east-1 VGW advertising prefixes via BGP. BGP ASN should be unique at these locations. VGW at us-east-1 will re-advertise these prefixes to the Washington office.
B.Using existing Internet connection in Chicago and Paris, set up a VPN connection with us-east-1 VGW advertising prefixes via BGP. BGP ASN should be unique at these locations. VGW at us-east-1 will re-advertise these prefixes to the Washington office.
C.Using existing Internet connection in Chicago and Paris, set up a VPN connection between us-west-1 and eu-west-3 regions.
D.Using existing Internet connection in Chicago and Paris, set up VPC peering connections from the branch offices to the VPC in the head office.

Correct Answer – B
Option A is incorrect as there is no need to setup Direct Connection in us-east-1.
Option B is CORRECT because VPN connection is suitable to establish the communications between the branch offices and the head office VPC.Option C is incorrect as the question needs to setup VPN connections between branch offices and the head office. 
Option D is incorrect as VPC peering connection is used for the connections between VPCs. In this question, the branch offices in Chicago & Paris do not use VPCs.
Please check the following diagram:
For more information on using VPN connections, please refer to the following reference:
https://docs.aws.amazon.com/vpn/latest/s2svpn/VPC_VPN.html