Explanation:
Box 1: Azure Resource Manager test toolkit
Use ARM template test toolkit
The Azure Resource Manager template (ARM template) test toolkit checks whether your template uses recommended practices. When your template isn't compliant with recommended practices, it returns a list of warnings with the suggested changes. By using the test toolkit, you can learn how to avoid common problems in template development.
Box 2: What-if operation
ARM template deployment what-if operation
Before deploying an Azure Resource Manager template (ARM template), you can preview the changes that will happen. Azure Resource Manager provides the what-if operation to let you see how resources will change if you deploy the template. The what-if operation doesn't make any changes to existing resources.
Instead, it predicts the changes if the specified template is deployed.
Reference:
https://docs.microsoft.com/en-us/azure/azure-resource-manager/templates/test-toolkit
https://docs.microsoft.com/en-us/azure/azure-resource-manager/templates/deploy-what-if

https://learn.microsoft.com/en-us/azure/cosmos-db/consistency-levels

Explanation:
Step 1: az extension add --name azure-cli-iot-ext
Run the following command in the command-line environment where you are using the Azure CLI to install the IoT extension:
az extension add --name azure-cli-iot-ext
Step 2: az iot hub device-identity create
--hub-name {Hub01}
--device-id Sensor00
Create a new device identity called myDeviceId and retrieve the device connection string with these commands:
az iot hub device-identity create --device-id myDeviceId --hub-name {Your IoT Hub name} az iot hub device-identity show-connection-string --device-id myDeviceId --hub-name {Your IoT Hub name} -o table Step 3: az iot hub device-identity show-connection-string
--hub-name {Hub01}
--device-id Sensor00
--output table
Step 4:
Create the service app
In this section, you create a Node.js console app that adds location metadata to the device twin.
npm install azure-iothub --save
References:
https://docs.microsoft.com/en-us/azure/iot-hub/iot-hub-node-node-twin-getstarted

The Azure Service Bus Queue and Topic has duplicate detection.
Enabling duplicate detection helps keep track of the application-controlled MessageId of all messages sent into a queue or topic during a specified time window.
Incorrect Answers:
C: There is just no mechanism that can query a Storage queue and find out if a message with the same contents is already there or was there before.
D: Azure Event Hub does not have duplicate detection
Reference:
https://docs.microsoft.com/en-us/azure/service-bus-messaging/duplicate-detection