Monitor and maintain Azure resources

The correct answer is to Configure the dimension splitting settings to group the query evaluation by the '_ResourceId' column.

By default, a log search alert rule created on a Log Analytics workspace targets the workspace resource itself. Consequently, any fired alert is associated with the workspace, not the individual virtual machines generating the logs. Since your Alert Processing Rule is scoped to the 'Compute-RG' (where the VMs reside) and not the workspace, it fails to suppress alerts targeting the workspace.

By configuring the alert rule to split by dimensions using the '_ResourceId' column, the alert engine analyzes the log data and generates separate alert instances for each unique resource found. Crucially, this changes the target of the fired alert from the generic workspace to the specific Azure resource instance (the VM). Once the alert targets the VM resource, it falls within the scope of the 'Compute-RG', allowing the Alert Processing Rule to successfully apply the suppression logic during the maintenance window.

Regarding the other options:
- Enabling a system-assigned managed identity addresses authentication and permission scopes for running the query, not the association of the resulting alert instance to a specific resource.
- Updating aggregation granularity helps with data consistency and ingestion latency issues but does not change the target resource context of the fired alert.
- Refining the Kusto query to project the 'Computer' field is a step in data preparation, but without explicitly configuring the alert rule settings to 'Split by dimensions' on a resource identifier, the alert system will still treat the Workspace as the primary target resource.

The Network Watcher Agent extension is the correct answer.

To utilize Network Watcher features such as Connection Monitor, Packet Capture, and IP Flow Verify on an Azure virtual machine, the Network Watcher Agent extension must be installed and enabled. This extension is responsible for generating the traffic required to test reachability and measure latency, as well as collecting the necessary network telemetry.

Why the other answers are incorrect:
- The Azure Monitor Dependency agent is used primarily by Azure Monitor (specifically VM Insights and Service Map) to visualize dependencies and connections between server processes, rather than facilitating the active network tests performed by Network Watcher.
- The Performance Diagnostics extension is designed to troubleshoot virtual machine performance issues, such as high CPU or memory consumption, rather than network connectivity.
- The Guest Configuration extension is used in conjunction with Azure Policy to audit or apply configurations inside the operating system, unrelated to network monitoring.

The correct action is to deploy new instances of both vault types, configure the encryption properties using the customer-managed keys, and then configure protection for the resources in the new vaults.

Azure Backup allows the configuration of Customer-Managed Keys (CMK) for encryption at rest. However, a critical limitation exists regarding when this configuration can be applied. For Recovery Services vaults, encryption settings using CMK can only be configured at the time of creation or before any items have been protected to the vault. Once a vault contains backup items or is actively protecting resources, you cannot switch from platform-managed keys to customer-managed keys. The same limitation generally applies to Backup vaults where the encryption properties are set during deployment or before protection is initialized.

Because the scenario states that the vaults are 'active' (implying they already contain backup data or registered items), you cannot simply update the encryption settings of the existing resources. Therefore, the only viable path to compliance is to create new vaults, enable CMK immediately upon creation/before registration, and then protect the workloads using these new vaults.

Why the other answers are incorrect:

• Assigning a managed identity and updating properties works for enabling CMK on vaults that are empty or new, but because the existing vaults are active and already populated, the platform prevents changing the encryption method to CMK.
• Configuring Managed Identity verification and changing encryption types faces the same restriction: active vaults containing backup data cannot be migrated from platform-managed to customer-managed encryption.
• Enabling infrastructure encryption is a separate feature (double encryption) and does not address the specific requirement to switch the primary encryption key from platform-managed to customer-managed for active vaults, nor does it bypass the restriction on modifying active vaults.