You have a web application named WebApp1. You need to enable claims-based
authentication on WebApp1. Which tool should you use?

A.
Internet Information Services (IIS) Manager

B.
the Stsadm command

C.
the Set-SPWebApplication cmdlet

D.
Central Administration

Explanation:
When you provision a web application in SharePoint 2013 you get the option to enable Claims based
authentication. However, after the provisioning there’s no option in the GUI to turn it on. PowerShellsaves the
day again with the option to change from classic toclaims based authentication using the lines below.
$WebAppName = “http://test:8001”
$account = “Administrator”
$wa = get-SPWebApplication $WebAppName
Set-SPwebApplication $wa AuthenticationProvider (New-SPAuthenticationProvider)
Zone Default
The user running these command should be a member of the SharePoint_Shell_Access role on the config DB,
and a member of the WSS_ADMIN_WPG local group.
http://sharepoint2013mind.blogspot.com/2012/02/enable-claims-based-authentication-on.html