In which scenarios is it necessary to explicitly commit a bundle?

The correct choice revolves around understanding the context of bundle management within Guidewire applications. When working with web services that perform database alterations and modify entities that are returned to clients, it is essential to explicitly commit a bundle to ensure that all changes are saved and reflected in the database.

In Guidewire, a bundle represents a set of related changes to the data model that can be committed as a single transaction. This is crucial in web service scenarios because operations often involve multiple changes, and it is important to maintain data integrity. By committing a bundle, the application can ensure that all updates are either successfully applied together or not at all, which aligns perfectly with the atomic nature of web service transactions.

The other options present scenarios that either do not explicitly require bundle commits or represent specific use cases that are not as universal. Local applications or batch updates may work differently regarding transaction management, and e-commerce transactions may not inherently necessitate explicit bundle commits at all times. Hence, the focus on web services highlights the critical nature of managing database changes properly within the Guidewire framework.