Which strategy should a solutions architect recommend to meet this requirement?

Explanations:

While deploying an Amazon ElastiCache cluster could help reduce read costs by caching frequently accessed data, it does not directly address the issue of managing costs associated with the on-demand capacity of DynamoDB. It would also add complexity to the architecture.

Deploying DynamoDB Accelerator (DAX) can improve read performance, and configuring auto-scaling can help optimize costs, but on-demand mode is not suitable for a predictable pattern of traffic. Savings Plans can reduce costs but are not a complete solution on their own.

Switching to provisioned capacity mode can potentially lower costs if the read and write patterns are predictable. However, it does not address the need for improved read performance, which DAX could provide, and it lacks the benefits of using DAX for caching.

Deploying DynamoDB Accelerator (DAX) enhances read performance by caching frequently accessed items, reducing the number of reads directly from DynamoDB. Using provisioned capacity mode allows the company to control costs based on expected usage. Configuring auto-scaling optimizes capacity according to actual traffic patterns, further reducing costs.