Option B is the correct answer because it leverages Azure AD, a core component of Microsoft Fabric, for comprehensive user authentication and authorization. By utilizing Azure AD groups, you can efficiently manage access to specific items within the workspace, ensuring scalability and adherence to the principle of least privilege. Option A is less efficient as it requires creating multiple workspaces, which can lead to management overhead. Option C is incorrect because it focuses on managing access keys rather than directly controlling access to Fabric items. Option D is impractical due to the manual effort required and the potential for errors in large environments.