This explanation is based on AWS documentation and best practices but is paraphrased, not a literal extract.

The company needs two things:

To serve static content from the AWS Region geographically closest to each customer.

To send data from on premises to Amazon S3 with minimal latency and without traversing the public internet, while keeping operational overhead low.

S3 Multi-Region Access Points provide a single global endpoint that fronts multiple S3 buckets in different Regions. Multi-Region Access Points use latency-based routing and failover capabilities to direct client requests automatically to the closest healthy Regional S3 bucket that is part of the Multi-Region Access Point. This directly addresses the requirement to serve content from the closest Region with high performance and reliability, and it avoids the need to build and maintain custom routing logic.

Behind the scenes, S3 Multi-Region Access Points rely on S3 Replication between the Regional buckets that participate in the Multi-Region Access Point. When you configure a Multi-Region Access Point, you set up the participating buckets and replication configuration once; AWS then manages routing and failover, reducing operational overhead compared to manually configuring and managing multiple S3 endpoints and application logic.

For the on-premises environment, the company wants to send data to S3 with minimal latency and without using the public internet. AWS Direct Connect provides a dedicated network connection from the on-premises network into AWS, avoiding the public internet and generally providing lower and more consistent latency. AWS PrivateLink allows private connectivity to supported AWS services (such as S3 Multi-Region Access Points via interface endpoints) from within a VPC using private IP addresses. When you combine Direct Connect with PrivateLink, traffic flows from on-premises over a private dedicated connection into a VPC and then privately to the Multi-Region Access Point through an interface VPC endpoint, satisfying the requirement for no public internet exposure.

Therefore, implementing S3 Multi-Region Access Points (option A) addresses the global content serving and Regional routing, and using AWS PrivateLink together with AWS Direct Connect (option E) provides low-latency, private network connectivity from on premises to the Multi-Region Access Point with minimal operational overhead.

Option B, S3 Cross-Region Replication alone, would replicate data across Regions but would not automatically route customers to the closest Region; application changes and manual routing would be required, increasing operational overhead.

Option C would require building and maintaining a custom Lambda-based routing system, which is unnecessary when S3 Multi-Region Access Points provide managed routing and failover.

Option D, AWS Site-to-Site VPN, encrypts traffic over the public internet; it does not satisfy the explicit requirement to avoid public internet exposure and typically has less predictable latency than Direct Connect.