An administrator wants to automate an account permissions update for a large number of accounts. Which of the following would best accomplish this task?

User provisioning is the automated process of creating, updating, and deleting user accounts and their associated permissions across various systems and applications. This is the most efficient method for managing permissions for a large number of accounts, as it allows administrators to define rules and policies that automatically apply changes. Security groups are used to assign permissions to multiple users simultaneously, but they don't automate the update process itself. Federation allows users to access resources across different domains with a single set of credentials, but it doesn't directly address automated permission updates. Vertical scaling refers to increasing the capacity of a single server or resource, which is unrelated to account management.