The Dream House Realty (DR) service manager asks for some Improvements in case management.

The correct answer is D.

Validation rules are the right declarative tool to enforce data compliance before a record is saved. They can prevent a Case from moving backward to an earlier Status and can require specific fields when Case criteria are met. Salesforce formula functions such as ISCHANGED() compare whether a field value changed, and validation rules can use formula logic to stop invalid saves.

Why others are incorrect:

Approval Process is for routing records for approval.

Dependent picklists control picklist value availability, not status regression.

Case Flow can automate case processes, but validation rules are the best tool for enforcing save-time compliance.

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