What should you do?

You need to resolve the Active Directory issue.

What should you do?
A . Run the IdFix tool then use the Update actions.
B . From Active Directory Domains and Trusts, modify the list of UPN suffixes.
C . From Azure AD Connect, modify the outbound synchronization rule.
D . From Active Directory Users and Computers, select the user accounts and then modify the UPN suffix value.

Answer: A

Explanation:

IdFix is used to perform discovery and remediation of identity objects and their attributes in an on-premises Active Directory environment in preparation for migration to Azure Active Directory. IdFix is intended for the Active Directory administrators responsible for directory synchronization with Azure Active Directory.

Scenario: Active Directory Issue Several users in humongousinsurance.com have UPNs that contain special characters. You suspect that some of the characters are unsupported in Azure AD.

References:

https://www.microsoft.com/en-us/download/details.aspx?id=36832