Which AWS service could improve efficiencies by offloading requests from the main database?

The correct choice, which is the use of Read Replicas in Amazon RDS, effectively addresses the need to improve efficiencies by offloading requests from the main database. Read Replicas enable you to create one or more copies of your database instance, primarily for read operations. By distributing read loads to these replicas, the main database can focus on handling write operations and critical tasks, leading to enhanced performance and response times for applications.

Read Replicas are particularly beneficial for workloads that involve heavy read traffic, allowing you to scale your database read operations horizontally. This setup not only improves throughput but also minimizes latency, improving overall application performance.

Considering the context of other options, AWS DynamoDB is a fully managed NoSQL database service that provides single-digit millisecond performance at scale. While it efficiently handles read workloads, it doesn’t specifically act to offload requests from another database like RDS does with Read Replicas.

AWS Lambda is a serverless compute service that allows you to run code in response to events without provisioning or managing servers. Although it can be used in conjunction with databases, it doesn't directly offload requests from a main database.

AWS ElastiCache is an in-memory data store and cache service that can accelerate database workloads by providing sub-millisecond