To prevent overwriting previous functionality due to Auto-Resolve, what should be excluded for new promotions?

The correct choice focuses on ensuring that Auto-Resolve doesn't overwrite important changes made in the development environment. Excluding Apex Classes in the Pipeline Record is essential because this is where the merge strategy for the deployment is managed. By doing so, you avoid potential conflicts between newly developed promotions and existing functionality, ensuring that previously deployed code is not unintentionally modified.

The Pipeline Record is specifically designed to manage the flow of changes that occur throughout the deployment process. If Apex Classes were included in Auto-Resolve, there could be situations where newer changes overwrite existing code, leading to regression issues or loss of functionality that was intended to be maintained.

The other options involve Apex Classes in different contexts, such as User Story Records, Destination's Org Credentials, and Deployment Records, but they do not directly relate to the primary concern of managing how changes are merged during the promotion process. Thus, focusing on the Pipeline Record is crucial for maintaining the integrity of previously established functionalities.