You have a multi-tier application (App1) whose backend service writes to an Azure SQL database (SQL1). Client users read data via the App1 client and experience significant delays retrieving data during peak load. Which service should you include to minimize data retrieval latency for the users?

Azure Cache for Redis is an in-memory data store that significantly reduces data retrieval latency by caching frequently accessed data. By placing a cache between App1 and SQL1, read requests for common data can be served directly from the fast in-memory cache instead of querying the slower database, especially during peak loads. Azure Content Delivery Network (CDN) is used for caching static web content closer to users globally, not for dynamic database query results. Azure Data Factory is a data integration service for orchestrating data movement and transformation, not for real-time caching. Azure Synapse Analytics is an analytics service for large-scale data warehousing and big data analytics, not for improving transactional application read performance.