App Gateway will balance the traffic between VMs deployed in the same region. Create an Azure Traffic Manager profile instead.

Instead: you should recommend using an Azure Policy initiative to enforce the location.
Note: Azure Resource Policy Definitions can be used which can be applied to a specific Resource Group with the App Service instances.
In Azure Policy, we offer several built-in policies that are available by default.
For example:
* Allowed Locations (Deny): Restricts the available locations for new resources. Its effect is used to enforce your geo-compliance requirements.
Reference:
https://docs.microsoft.com/en-us/azure/governance/policy/overview

You need to create a system topic and enable managed identity for the storage account.
Note:
In Azure, a System Topic is a built-in channel within Azure Event Grid that automatically handles and routes events from specific Azure services (like Storage, Event Hubs) to interested subscribers, acting as a pre-configured event source without requiring manual setup of endpoints or keys for publishing. It simplifies event-driven architectures by providing a dedicated, managed topic for events like BlobCreated or ResourceDeleted, letting you focus on what happens after the event.
Reference:
https://learn.microsoft.com/th-th/azure/event-grid/system-topics
https://learn.microsoft.com/en-us/azure/event-grid/handler-event-grid-namespace-topic

Explanation:
Box 1: Premium block blobs
Azure Storage provides data protection for Blob Storage and Azure Data Lake Storage Gen2 to help you to prepare for scenarios where you need to recover data that has been deleted or overwritten.
Data protection refers to strategies for protecting the storage account and data within it from being deleted or modified, or for restoring data after it has been deleted or modified.
* Prevent new data from being modified for one year.
Box 2: Read-access geo-redundant storage (RA-GRS)
RA-GRS has better data protection compared to ZRS and LRS.
* Maximize data resiliency.
* Minimize read latency.
Reference: https://docs.microsoft.com/en-us/azure/storage/blobs/data-protection-overview

Azure provides several disaster recovery tools for container-based workloads. To protect the multi-region Azure Kubernetes Service deployments from the regional outages, you need to implement Azure Traffic Manager. Azure Traffic Manager is a global load balancing service based on DNS.
It provides high availability and disaster recovery for container-based workloads. If one region fails, Azure Traffic Manager will direct the traffic to the secondary region. Traffic Manager routes any protocol (not only HTTP/HTTPS as Azure Front Door or Azure Application Gateway does) to the service endpoint's public IP address based on the routing method. Using geographic routing, it will direct the traffic to the closest AKS cluster and application instance. Then, the Load Balancer will take care of data delivery to the AKS.
Option A is incorrect because you need to use the Traffic Manager and Load Balancer services for multi-region AKS protection from the regional outages, but not the Azure Backup service.
However, the Azure Backup service protects the application data. Your container-hosted application uses Azure Storage disks or file shares, and Azure Backup will be an appropriate data recovery service.
Option B is incorrect because you need to use the Traffic Manager and Load Balancer services for multi-region AKS protection from the regional outages, but not the Azure VM Scale sets.
However, in case of node failures, Azure Kubernetes Service uses VM Scale sets to protect the nodes.
Option D is incorrect because you need to use the Traffic Manager service and Load Balancer services for multi-region AKS protection from the regional outages, but not the Azure App Service. Azure App Service is a fully managed web application hosting platform.
Reference:
https://docs.microsoft.com/en-us/azure/aks/operator-best-practices-multi-region#use-azure-traffic-manager-to-route-traffic
https://docs.microsoft.com/en-us/azure/traffic-manager/traffic-manager-configure-geographic-routing-method
https://docs.microsoft.com/en-us/azure/traffic-manager/traffic-manager-configure-geographic-routing-method