Your Azure AD tenant contains 500 users and an administrative unit named AU1. From the Azure AD admin center you plan to add members to AU1 using Bulk add members. What should the uploaded file contain?

When performing a bulk add of members to an administrative unit in Azure AD, the system specifically requires a CSV file containing only the User Principal Name (UPN) of each user. The UPN is a unique identifier for each user in Azure AD, making it the definitive attribute for identifying and adding users in bulk operations. Including additional attributes like display name or object identifier would cause the bulk operation to fail, as the system expects a specific format. While object identifiers are unique, the bulk add function is designed to work with UPNs for user identification.