The business owner is the best suited role to validate user access requirements during an annual user access review, because the business owner is responsible for determining the business needs and objectives of the users, as well as defining the appropriate access rights and privileges for each user role. The business owner is also accountable for ensuring that the user access is aligned with the organization's policies and standards, and that the user access review is conducted effectively and efficiently1. The access manager, the IT director, and the system administrator are not as suitable as the business owner, because they are more involved in the technical and operational aspects of user access management, rather than the business aspects.
References = Effective User Access Reviews