You have an Azure Active Directory (Azure AD) tenant that contains 500 users and an administrative unit named AU1. From the Azure Active Directory admin center,...

You have an Azure Active Directory (Azure AD) tenant that contains 500 users and an administrative unit named AU1.
From the Azure Active Directory admin center, you plan to add the users to AU1 by using Bulk add members.
You need to create and upload a file for the bulk add.
What should you include in the file?

A. only the display name of each user B. only the user principal name (UPN) of each user C. only the user principal name (UPN) and display name of each user D. only the user principal name (UPN) and object identifier of each user E. only the object identifier of each user