Which types of programs cannot be tested directly from the ABAP Workbench?

Type-Pools in ABAP represent a collection of global type definitions and are used primarily to define data types, such as structures and table types, that can be shared across different programs. Unlike other code units such as class-pools, method implementations, or function pools, they do not contain executable code and therefore do not have a flow of execution that can be tested directly.

When working with the ABAP Workbench, testing usually involves directly executable programs or objects that can be run in isolation or as part of an application. However, since type-pools serve as a repository for type definitions rather than implementing functionality, they can only be utilized through other executable units but cannot be tested by themselves. This is why Type-Pools are the correct answer to the question regarding which types of programs cannot be tested directly from the ABAP Workbench.

In contrast, class-pools, method implementations, and function-pools contain executable code and can be tested through different testing frameworks or directly executed, making them suitable for debugging and operational testing.