What should the solutions architect do to accomplish this goal?

Explanations:

Storing product manuals on EBS volumes and mounting them to EC2 instances would not address the problem of keeping data updated across instances. EBS volumes are tied to specific EC2 instances, meaning that new instances would not automatically have the latest data unless you manually replicate or sync data between instances, which is not efficient for scaling.

Storing the product manuals in an S3 bucket and redirecting downloads to the bucket is a good option for static content, but it does not address the need for resizing the EBS volumes during business hours. Additionally, while S3 provides scalability, it doesn’t solve the issue of syncing data between the EC2 instances and auto-scaling quickly.

Storing the product manuals in Amazon EFS and mounting it to EC2 instances ensures that all instances have access to the most up-to-date data without the need to sync or manage individual EBS volumes. EFS is a fully managed, scalable file storage system that can be mounted by multiple EC2 instances across different availability zones, making it ideal for sharing data across instances launched by an Auto Scaling group.

Storing the product manuals in an S3 Standard-IA bucket is not ideal for frequent access patterns such as in the case of product manual downloads. S3 Standard-IA is intended for data that is infrequently accessed, and the retrieval cost for frequently accessed data would be higher. S3 would not provide the same seamless integration as EFS for instances needing constant access to the latest data.