https://docs.microsoft.com/en-us/azure/active-directory/authentication/howto-mfa-mfasettings

Reference:
https://docs.microsoft.com/en-us/azure/azure-monitor/platform/autoscale-best-practices

Explanation

This reference architecture shows how to deploy VMs and a virtual network configured for an N-tier application, using SQL Server on Windows for the data tier.

Scenario: You have a public-facing application named App1. App1 is comprised of the following three tiers:
* A SQL database
* A web front end
* A processing middle tier
Each tier is comprised of five virtual machines. Users access the web front end by using HTTPS only.
* Technical requirements include:
* Move all the virtual machines for App1 to Azure.
* Minimize the number of open ports between the App1 tiers.
References: https://docs.microsoft.com/en-us/azure/architecture/reference-architectures/n-tier/n-tier-sql-server

Explanation

Not VM1 because it has BitLocker enabled.
Not VM2 because the OS disk is larger than 2TB.
Not VMC because the Data disk is larger than 4TB.
References:
https://docs.microsoft.com/en-us/azure/site-recovery/hyper-v-azure-support-matrix#azure-vm-requirements

You can move an app to another App Service plan, as long as the source plan and the target plan are in the same resource group and geographical region.
The region in which your app runs is the region of the App Service plan it's in. However, you cannot change an App Service plan's region.
References: https://docs.microsoft.com/en-us/azure/app-service/app-service-plan-manage