Which combination of steps will meet these requirements with the LEAST operational overhead?

Explanations:

AWS Storage Gateway Volume Gateway is designed for hybrid cloud storage, not for reducing bandwidth for remote access. Mounting a volume on an on-premises file server does not address the issue of remote workers or reduce operational overhead.

Migrating the home directories to Amazon FSx for Windows File Server allows the company to store the files in a managed, scalable service optimized for Windows workloads. This reduces reliance on the on-premises data center and offloads file storage to AWS, which can reduce bandwidth usage.

FSx for Lustre is a high-performance file system used primarily for workloads with high throughput and low-latency requirements. It is not ideal for Windows-based file storage or home directories.

Migrating remote users to AWS Client VPN will provide a scalable and secure VPN solution directly to AWS, reducing the reliance on the on-premises VPN and offloading some of the traffic from the data center. This reduces the bandwidth congestion.

AWS Direct Connect provides a dedicated, high-bandwidth connection between an on-premises data center and AWS. While it could improve performance, it does not reduce operational overhead or address the challenge of increasing remote worker connections directly.