What does Amazon ElastiCache provide?

Correct answer: In-memory caching for improved application performance

Option D is correct because Amazon ElastiCache is a fully managed in-memory data store and cache service that supports Redis and Memcached engines, dramatically reducing database load and improving application response times by serving frequently accessed data from memory rather than disk. Option A is incorrect because serverless compute is provided by AWS Lambda, not ElastiCache, which is a managed caching layer rather than a compute platform. Option B is incorrect because DNS management is the domain of Amazon Route 53, which handles domain registration, routing policies, and health checks. Option C is incorrect because managed file storage is provided by services such as Amazon EFS or Amazon FSx; ElastiCache is an in-memory key-value store, not a persistent file system.