Using topic client, call RegisterMessageHandler which is used to receive messages continuously from the entity. It registers a message handler and begins a new thread to receive messages. This handler is waited on every time a new message is received by the receiver.
subscriptionClient.RegisterMessageHandler(ReceiveMessagesAsync, messageHandlerOptions);
Reference:
https://www.c-sharpcorner.com/article/azure-service-bus-topic-and-subscription-pub-sub/

https://learn.microsoft.com/en-us/azure/azure-cache-for-redis/cache-web-app-howto

Explanation

Box 1: role-based access control (RBAC)
Azure Storage supports authentication and authorization with Azure AD for the Blob and Queue services via Azure role-based access control (Azure RBAC).
Scenario: File access must restrict access by IP, protocol, and Azure AD rights.
Box 2: storage account type
Scenario: The website uses files stored in Azure Storage
Auditing of the file updates and transfers must be enabled to comply with General Data Protection Regulation (GDPR).
Creating a diagnostic setting:
1. Sign in to the Azure portal.
2. Navigate to your storage account.
3. In the Monitoring section, click Diagnostic settings (preview).

4. Choose file as the type of storage that you want to enable logs for.
5. Click Add diagnostic setting.
Reference:
https://docs.microsoft.com/en-us/azure/storage/common/storage-introduction
https://docs.microsoft.com/en-us/azure/storage/files/storage-files-monitoring

Explanation
Box 1: Docker container
A custom handler can be deployed to every Azure Functions hosting option. If your handler requires operating system or platform dependencies (such as a language runtime), you may need to use a custom container. You can create and deploy your code to Azure Functions as a custom Docker container.
Box 2: PowerShell core
When creating a function app in Azure for custom handlers, we recommend you select .NET Core as the stack.
A "Custom" stack for custom handlers will be added in the future.
PowerShell Core (PSC) is based on the new .NET Core runtime.
Box 3: 7.0
On Windows: The Azure Az PowerShell module is also supported for use with PowerShell 5.1 on Windows.
On Linux: PowerShell 7.0.6 LTS, PowerShell 7.1.3, or higher is the recommended version of PowerShell for use with the Azure Az PowerShell module on all platforms.
Reference:
https://docs.microsoft.com/en-us/azure/azure-functions/functions-create-function-linux-custom-image
https://docs.microsoft.com/en-us/powershell/azure/install-az-ps?view=azps-7.1.0

The correct answer is A, B, and C. To inspect request processing of the APIs in APIM, you need to do the following three actions:
Enable the Allow tracing setting for the subscription used to inspect the API. This setting allows you to trace request processing in APIM using the test console, a REST client, or a client app. You can enable this setting in the portal by selecting Subscriptions and then selecting the subscription you want to use for debugging1.
Add the Ocp-Apim-Trace header value to the API call with a value set to true. This header triggers tracing when making requests to APIM using a REST client or a client app. You also need to add the Ocp-Apim-Subscription-Key header value to the key for a subscription that allows access to the API1.
Add the Ocp-Apim-Subscription-Key header value to the key for a subscription that allows access to the API. This header authenticates your request and grants you access to the API. You can find the key for your subscription in the portal by selecting Subscriptions and then selecting Show/hide keys1.
You do not need to create and configure a custom policy for tracing request processing. The trace policy is used to add a custom trace into the request tracing output, Application Insights telemetries, and/or resource logs2. It is not required for inspecting the APIs.