In the scenario of managing data relationships for an eCommerce site:

B. Create a one-to-many relationship between Orders and Order_Details: This relationship allows multiple order details (such as individual items, quantities, and prices) to be associated with a single order, reflecting the typical structure of an eCommerce transaction.

D. Create a one-to-one relationship between Order_Details and Products: This relationship links each order detail line to a specific product, allowing for detailed tracking and analysis of product sales.

These relationships set up a logical and functional structure in Data Designer, enabling effective data management and utilization for reporting and customer insights.