What should the solutions architect do to meet these requirements?

Explanations:

AWS Migration Hub is primarily used for tracking and managing the migration of applications and data between AWS and on-premises environments. It does not provide the capability to securely transfer large amounts of data with encryption during transit, nor does it directly address the low bandwidth issue for transferring 60 TB of data.

AWS Storage Gateway allows integration between on-premises environments and AWS, but the volume gateway is typically used for block storage and caching. It does not inherently provide the required encryption during transit or optimize for low bandwidth, and it is not the most efficient option for transferring such a large dataset.

Amazon EFS is a managed file storage service for use with AWS Cloud services and on-premises resources. However, it does not natively support direct export to on-premises environments securely and efficiently for large data volumes, nor does it offer specific features to manage low-bandwidth transfers effectively.

Deploying an AWS Snowball device allows for secure, encrypted data transfer for large amounts of data (up to 80 TB per device) to be physically transported to the on-premises data center. Snowball supports encryption during transit, addresses low bandwidth issues by transferring data via physical means, and is well-suited for fulfilling the quarterly audit requirements.