DynamoDB Accelerator DAX is the best answer because it is a fully managed in-memory cache built specifically for DynamoDB. AWS documentation states that DAX is highly available, is designed for read-heavy workloads, and can deliver major latency improvements while reducing direct reads to DynamoDB. The question highlightskey-based lookupsandthroughput exceedederrors, which is the classic DAX use case. ElastiCache could be made to work, but it requires more application-side cache management and is not as tightly integrated with DynamoDB. Simply increasing read capacity manually is less cost-efficient and less adaptive. Copying the data to RDS adds unnecessary complexity and architectural drift. For the fewest changes and best DynamoDB-specific optimization, DAX is the correct answer. (AWS Documentation)

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