In Tableau Server, roles and permissions dictate who can perform specific administrative tasks. A "server administrator" has full control over the entire Tableau Server deployment, while site administrators manage specific sites. Some tasks are restricted to server administrators due to their server-wide impact.
Option B (Adding a site): Creating a new site in a multi-site Tableau Server environment is a server-level task that only a server administrator can perform. Sites are logical partitions within the server, and adding a site affects the overall server structure. Site administrators cannot create new sites; they can only manage existing ones.
Option D (Adding users): Adding users to Tableau Server (e.g., via the TSM interface or tabcmd) is a server administrator task when it involves adding users at the server level or assigning them to the default site. While site administrators can add users to their specific site in a multi-site environment, the initial addition of users to the server requires server administrator privileges. The question's phrasing ("always require") suggests a server-wide context, making this a correct choice.
Option A (Creating a schedule): This is incorrect because both server administrators and site administrators can create schedules for tasks like extract refreshes or subscriptions within their scope. It's not exclusive to server administrators.
Option C (Locking project permissions): This is incorrect because locking project permissions can be done by a site administrator or project leader with appropriate permissions. It's a project-level action, not a server- level task requiring a server administrator.