What should you implement?

You need to implement the security requirements.

What should you implement?
A . the GraphAPI to query the directory
B . LDAP to query the directory
C . single sign-on
D . user certificates

Answer: C

Explanation:

https://blogs.msdn.microsoft.com/plankytronixx/2010/11/27/single-sign-on-between-on-premise-apps-windows-azure-apps-and-office-365-services/