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:
The Azure Active Directory Graph API provides programmatic access to Azure AD through REST API
endpoints. Applications can use the Graph API to perform create, read, update, and delete (CRUD)
operations on directory data and objects. For example, the Graph API supports the following common
operations for a user object:
/ Create a new user in a directory
/ Get a user’s detailed properties, such as their groups
/ Update a user’s properties, such as their location and phone number, or change their password
/ Check a user’s group membership for role-based access
/ Disable a user’s account or delete it entirely

Azure AD Graph API
URL: http://msdn.microsoft.com/en-us/library/azure/hh974476.aspx