You develop a set of Power Shell scripts that will run when you deploy new virtual machines (VMs).
You need to ensure that the scripts are executed on new VMs. You want to achieve this goal by using the
least amount of administrative effort.
What should you do?

A.
Create a new GPO to execute the scripts as a logon script.

B.
Create a SetupComplete.cmd batch file to call the scripts after the VM starts.

C.
Create a new virtual hard disk (VHD) that contains the scripts.

D.
Load the scripts to a common file share accessible by the VMs.

E.
Set the VMs to execute a custom script extension.

Explanation:
After you deploy a Virtual Machine you typically need to make some changes before it’s ready to use. This
is something you can do manually or you could use Remote PowerShell to automate the configuration of
your VM after deployment for example.But now there’s a third alternative available allowing you customize your VM: the CustomScript extension.
This CustomScript extension is executed by the VM Agent and it’s very straightforward: you specify which
files it needs to download from your storage account and which file it needs to execute. You can even
specify arguments that need to be passed to the script. The only requirement is that you execute a .ps1
file.

Customizing your Microsoft Azure Virtual Machines with the new CustomScript extension
http://fabriccontroller.net/blog/posts/customizing-your-microsoft-azure-virtual-machines-with-the-newcustomscript-extension/