A company has an application deployed in two Regions with one VPC per Region (non-overlapping private CIDRs). The company needs to connect both VPCs to a single on-premises data center for testing. The application can use up to 800 Mbps. Which design provides the required connectivity with the least operational overhead?

The correct option uses Site-to-Site VPN with BGP. This is because the requirement is to connect two separate VPCs (in different Regions) to a single on-premises data center. Site-to-Site VPN connections are designed for this purpose, establishing secure tunnels over the internet. BGP (Border Gateway Protocol) offers dynamic routing, which automatically propagates route changes and reduces operational overhead compared to static routing, especially when dealing with multiple connections or network changes. The Direct Connect options are less suitable because while Direct Connect offers higher bandwidth and lower latency, it typically involves more setup time and cost. Also, the question specifies "least operational overhead," and managing two separate private virtual interfaces for each VPC over a single Direct Connect link to a single data center can be more complex than two distinct VPN tunnels. The Direct Connect option with OSPF is also incorrect because AWS Direct Connect private virtual interfaces primarily support BGP for dynamic routing with customer gateways, not OSPF. The Site-to-Site VPN option with static routes is less optimal than BGP because static routes require manual updates whenever network topology changes, increasing operational overhead.