Deployment scope.
You can target your deployment to a resource group, subscription, management group, or tenant. Depending on the scope of the deployment, you use different commands.
To deploy to a resource group, use New-AzResourceGroupDeployment.
Incorrect:
Not C: To deploy to a tenant, use New-AzTenantDeployment.
Not D: To deploy to a subscription, use New-AzSubscriptionDeployment which is an alias of the New-AzDeployment cmdlet.
To deploy to a management group, use New-AzManagementGroupDeployment.
Not A: The New-AzResource cmdlet creates an Azure resource, such as a website, Azure SQL Database server, or Azure SQL Database, in a resource group.
Reference:
https://docs.microsoft.com/en-us/azure/azure-resource-manager/templates/deploy-powershell