Which statement is true about granting and revoking permission levels?

The statement that a DTA must have a permission level in order to grant or revoke that permission level is accurate. This is because permission management is designed to ensure that only authorized individuals can influence or change the permissions of others. A DTA, or Defense Travel Administrator, operates within the framework of the Defense Travel System and must possess the requisite authority or permission themselves to manage these permissions for others. This structure helps maintain security and accountability within the system, ensuring that permissions can only be modified by those who are qualified to do so.

In contrast, aspects such as granting permissions without prior assessment or allowing all users to revoke permissions irrespective of their own permission levels would undermine the integrity of the system. These false propositions could lead to unauthorized changes and potential misuse of the travel management system. Finally, the idea that revoking permissions does not affect existing travel documents is also misleading, as changing a user's permissions can have implications for their access and management of those travel documents.