Which of the following extensions are allowed on a CDS view that does not contain the annotation, ABAPCatalog.viewEnhancementCategory?

When working with Core Data Services (CDS) views in ABAP, enhancements and extensions are a crucial aspect of how these views can be developed and modified. The question revolves around the capabilities of extending a CDS view that does not have a specific annotation, namely, the ABAPCatalog.viewEnhancementCategory.

The correct choice, which allows further customization of the original CDS view, involves the addition of associations in the element list. This means that you can augment the existing model by defining new relationships between entities within the CDS view. Associations in CDS are designed to represent relationships, facilitating the ability to navigate through related data. Therefore, adding new associations is a permissible and expected way to enrich the original view without the limitation imposed by the specified annotation.

In contrast, other options are more restrictive. For instance, adding additional fields in the extension list might not adhere to the structure and integrity of the original view as delineated by the lack of the enhancement category annotation. Similarly, while expressions can be a powerful tool in CDS views, modifications to expressions that fundamentally change the context or intent of the original view could lead to potential inconsistencies or unintended consequences. Lastly, altering the GROUP BY clause could disrupt the aggregation logic inherent to the CDS view, potentially leading to