You need to ensure that SaasApp1 can access directory objects

You manage a software-as-a-service application named SaasApp1 that provides user
management features in a multi-directory environment. You plan to offer SaasApp1 to other
organizations that use Azure Active Directory. You need to ensure that SaasApp1 can
access directory objects. What should you do?

A.
Configure the Federation Metadata URL

B.
Register SaasApp1 as a native client application.

C.
Register SaasApp1 as a web application.

D.
Configure the Graph API.

Explanation:
Ref: http://msdn.microsoft.com/en-us/library/azure/hh974476.aspx