For a staged rollout involving different user groups, several data preparation steps are crucial to ensure a smooth transition. Dividing customer data into subsets allows for phased migration, targeting specific groups at different times. Configuring role-based access controls ensures that data access permissions are appropriately set for each group. Conducting tests with pilot groups helps identify and rectify issues before a full rollout. Thus, "D. All of the above, contributing to a controlled and efficient data migration process with minimal disruption to different user groups" best encapsulates the comprehensive approach needed for successful staged rollouts.
Reference: Salesforce Data Migration Best Practices