Final answer:
Installing Marketing Cloud Connect does indeed require administrative rights to both the Marketing Cloud and Sales or Service Cloud to configure settings and manage data access and security.
Step-by-step explanation:
The statement that Marketing Cloud Connect installation requires administrative rights to both Marketing Cloud and Sales or Service Cloud is true. For a successful integration, administrative permissions are necessary to configure settings and install packages in both systems. Without the necessary permissions, the integration could be incomplete or fail to function properly. This ensures that the user setting up the connection has the ability to manage settings, data access, and security settings in both environments, which is crucial for data synchronization and leveraging the full capabilities of Marketing Cloud Connect.