1. Investigate last Tuesday with no diagnostic setting

Use the platform metrics and the activity log. The resource logs for last Tuesday do not exist and cannot be produced.

This is the honest answer and the one the exam wants. Platform metrics and the activity log are automatically collected without configuration — a diagnostic setting only sends them somewhere else. Resource logs need the setting to be collected at all, and collection starts when the setting does. Creating one now fixes next Tuesday. Any option that recovers last week's resource logs is describing something impossible.

2. One alert per machine across thirty

Nothing to change — that is already the behaviour. Investigate why it did not happen.

If you're monitoring more than one resource, the alert rule condition is evaluated separately for each resource, and alerts are fired for each resource separately. So a single ticket for thirty machines points at the scope of the rule or at the action group's grouping, not at a missing per-resource setting. Reading the requirement as "add a rule per machine" is the expensive wrong answer.

3. Silence a rule tonight without losing it

An alert processing rule that suppresses notifications for that window.

Three objects, three jobs: the alert rule detects, the action group notifies, and the alert processing rule suppresses or redirects. Disabling the rule loses the detection; deleting the action group affects every rule using it. And note what cannot be done: fired alert instances are read-only and cannot be edited — configuration changes apply only to future alerts, so the hour's existing noise stays.

4. Recover a file deleted two days ago

Restore from Azure Backup.

Backups are stored in a Recovery Services vault with built-in management of recovery points, and a restore is how a deleted item comes back. Site Recovery is the wrong service here however plausible it looks in the option list — replicating a deletion is all it would have done. Budget for the restore: outbound data charges apply to data transferred from a vault during a restore.

5. Survive the region becoming unavailable

Azure Site Recovery.

Site Recovery keeps business apps and workloads running during outages by replicating to a secondary location; when an outage occurs you fail over and access apps from there, and fail back once the primary is running again. It answers availability, not recovery — which is why requirements 4 and 5 need two different services and neither substitutes for the other.