DRAG DROP
A company deploys an Office 365 tenant. You install the Active Directory Federation Services (AD FS)
server role on a server that runs Windows Server 2012. You install and configure the Federation
Service Proxy role service. Users sign in by using the Security Assertion Markup Language (SAML)
protocol.
You need to customize the sign-in pages for Office 365.
Which pages should you customize? To answer, drag the appropriate page to the correct
customization. Each page may be used once, more than once, or not at all. You may need to drag the
split bar between panes or scroll to view content.
Answer: 
Explanation:
http://msdn.microsoft.com/en-us/library/ee895359.aspx
HomeRealmDiscovery.aspx: Presents a selection UI for the user to select the organization to which he or she belongs.
IdpInitiatedSignOn.aspx: Presents a selection UI for the user to select an RP application to sign in to. This page only works for RP applications that use the SAML protocol.
MasterPages/MasterPage.master: A master page template for all the pages.
https://msdn.microsoft.com/en-au/library/ee895359.aspx
Usually posts some very fascinating stuff like this. If you are new to this site.