The Repeater Widget in CRM Analytics allows dynamic updates to be reflected on the dashboard automatically as data flows are updated. This means that as new account managers join or existing account managers change roles, the data in the widget will automatically reflect the latest information without manual updates. This is the most efficient way to keep the dashboard up-to-date with the current list of account managers.

Cluster transformation is a powerful tool in CRM Analytics recipes used for grouping similar records together based on shared attributes. In this scenario, Universal Containers (UC) wants to perform whitespace analysis by viewing a particular customer and comparing their purchase history with similar customers. The Cluster transformation would help in identifying groups of customers who have made similar purchases. This can then be used to provide insights into what the viewed customer might also be interested in purchasing, based on similar customer behaviors.
Reference: CRM Analytics Recipes and Transformation

To ensure that CRM Analytics dashboards are optimally usable on both desktop and mobile devices, creating multiple layouts tailored to each device type is crucial. Here's why Option C is the best approach:
Device-Specific Layouts: By creating specific layouts for each device type, you ensure that the dashboard contents are presented in a manner best suited to the screen size and interaction model of the device.
Layout Selectors: These are used to automatically display the appropriate layout based on the device accessing the dashboard, enhancing user experience without manual intervention.
Widget Customization: Resizing or hiding certain widgets for specific device layouts ensures that the dashboard remains clean, uncluttered, and easy to navigate, regardless of the device used.