The answer is B. Amazon RDS and E. Amazon EFS
Amazon RDS (Relational Database Service) is a managed database service that allows you to set up, operate, and scale a relational database. Amazon RDS can be used for read/write of constantly changing data as well as for storing structured data. It supports popular database engines such as MySQL, MariaDB, PostgreSQL, Oracle, and Microsoft SQL Server.
Amazon EFS (Elastic File System) is a simple, scalable, and fully managed file system that can be used to store and access data from multiple EC2 instances. It can be used for read/write of constantly changing data, as well as for storing unstructured data. Amazon EFS provides a shared file system that can be accessed by multiple EC2 instances at the same time, allowing you to share data between different compute instances.
Therefore, the correct answers are B. Amazon RDS and E. Amazon EFS.