Which report should an administrator use to determine user access to functionalities?

The correct choice is the Security Role report. This report is essential for understanding user access to various functionalities within the system. Security roles define the permissions and capabilities assigned to different users or groups within the organization. By reviewing the Security Role report, an administrator can see which functionalities are accessible to users based on their assigned roles, enabling effective management of user permissions and ensuring alignment with organizational policies.

In contrast, the other options provide insights that do not directly map to user access as clearly. The OU Hierarchy offers a structural overview of the organizational units but does not detail permissions or access levels. The User Record Audit tracks changes made to user records and activities but lacks specific information regarding the permissions a user has. Similarly, User Role Activities might indicate what users did or their engagement levels but do not comprehensively convey what functionalities they have access to. Therefore, the Security Role report is the most relevant tool for assessing user access to system functionalities.