D is correct because the requirement explicitly calls for (1) dedicated private connectivity, (2) automated and centrally managed operation, and (3) connectivity between on-premises data centers and multiple AWS Regions.
AWS Direct Connect provides dedicated private connectivity from on-premises environments to AWS. This is the key differentiator versus internet-based connectivity options when performance and consistency are required to meet strict SLAs.
AWS Cloud WAN provides centralized, policy-based management of a global network across Regions and on-premises attachments. Using Direct Connect attachments to Cloud WAN lets the company centrally define routing/segmentation policies and connect multiple data centers to multiple Regions in a consistent, automated way—well aligned to “automated and centrally managed” requirements for a multi-Region payment platform.
Why the other options are incorrect:
A (Global Accelerator) improves performance for internet-facing endpoints using Anycast and edge routing, but it does not provide private, dedicated connectivity between on-premises networks and AWS services. It is not the right tool for private HSM-to-AWS service connectivity.
B (Site-to-Site VPN + Transit Gateway) can be centrally routed with Transit Gateway, but VPN tunnels run over the public internet and are not “dedicated private connectivity.” They can be acceptable for many cases, but they do not best meet “dedicated private connectivity” and strict SLA expectations compared to Direct Connect.
C (CloudHSM) changes the architecture by moving tokenization into AWS-managed HSM infrastructure. The question states the company manages on-premises HSMs and needs private connectivity between those HSMs and AWS payment services, so replacing them with CloudHSM does not satisfy the stated connectivity requirement.
[References:, AWS Direct Connect Documentation: dedicated private connectivity from on premises to AWS; consistent network performance characteristics compared with internet-based paths, AWS Cloud WAN Documentation: centralized network management, policy-based connectivity across Regions, and support for attaching on-premises connectivity (including Direct Connect attachments), AWS Transit Gateway Documentation: centralized routing for VPC/on-prem connectivity (relevant comparison point for VPN-based designs), AWS Certified Solutions Architect – Professional (SAP-C02) Exam Guide: designing hybrid connectivity strategies, centralized network governance, and multi-Region architectures supporting strict performance requirements, , , , , , , ]