Which AWS service meets these requirements?

Explanations:

Amazon Aurora is a relational database service that supports SQL and can dynamically scale storage capacity. It also supports complex queries and table joins, making it suitable for the application’s requirements.

Amazon RDS for SQL Server is a managed relational database service but does not inherently provide the same level of dynamic scaling for storage as Aurora. It can perform table joins but may not scale as efficiently for varying workloads.

Amazon DynamoDB Streams is a feature of DynamoDB that allows you to capture changes to items in a table, but it is not a database service itself and does not support table joins as it is a NoSQL database.

Amazon DynamoDB on-demand provides a fully managed NoSQL database that scales automatically, but it does not support SQL features like table joins, making it unsuitable for applications requiring relational capabilities.