What statement must you insert to the following OData service to complete the navigation definition from the customer entity set to the corresponding sales orders?

What statement must you insert to the following OData service to complete the navigation definition from the customer entity set to the corresponding sales orders?

Service{ "sample.odata;; customer" as "Customer" navigates ("Customer_Orders" as "toOrders");"sample.odata: salesorders" as "Orders";}
A . Key specification
B . Aggregation
C . Join condition
D . Association

Answer: D