You create an application by using the Microsoft .NET Framework 3.5 and Microsoft ADO.NET.

The application contains a DataSet class. The DataSet class contains two tables named Order and OrderDetail as shown in the following exhibit.

You add a DataColumn class named OrderTotal to the Order table.
You need to ensure that the OrderTotal column stores the sum of the values in the LineTotal column of the OrderDetail table.

Which expression string should you use to set the Expression property of the OrderTotal column?

A.
“Sum(OrderDetail.LineTotal)”

B.
“Sum(Relationship.LineTotal)”

C.
“Sum(Order_OrderDetail.LineTotal)”

D.
“Sum(Child(Order_OrderDetail).LineTotal)”