AWS Certified Advanced Networking - Specialty (#52)

An organization will be expanding its current network design. When fully built out, there will be 99 VPCs spread across 11 AWS accounts (9 VPCs per account). There is currently an AWS Direct Connect connection into one account with 9 VPCs, each with a virtual network interface (VIF) per VPC. Which of the following designs will minimize cost while allowing the organization to expand?

Order 10 new Direct Connect connections, one from each of the accounts that will be provisioned. Create private VIFs in each account. Attach one private VIF per VPC.
Create a public VIF on the Direct Connect connection. Leverage the public VIF to create a VPN connection to each VPC.
Create hosted private VIFs in the existing account. Connect a private VIF to an AWS Direct Connect gateway in each account. Connect the gateway in each account to the VPCs.
Create a transit VPC in the existing account that consists of two routers in separate Availability Zones. Connect each VPC to the two routers in the transit VPC by using VPN.