Final answer:
Clicking Save & Close on a Validation Rule marks it as In Progress, triggering a Notification, which allows users to review Deployment Progress in the interface.
Step-by-step explanation:
When Dave clicks on Save & Close, the Validation Rule is immediately updated to In Progress. As in a metadata deployment, you will receive a Notification, and you can review the Deployment Progress in the interface by clicking on the appropriate link or button. This process indicates that changes have been initiated, and the system is working to apply the new validation rule. The notification typically provides information about the progress or completion of the task. By reviewing the Deployment Progress, users can ensure that their changes are being processed correctly and keep track of the deployment status.