You use Microsoft Visual Studio 2010 and Microsoft .NET Framework 4 to create an application. The application connects to a Microsoft SQL Server 2008 database. The database includes a table that contains information about all the employees. The database table has a field named EmployeeType that identifies whether an employee is a Contractor or a Permanent employee. You declare the Employee entity base type. You create a new Association entity named Contractor that inherits the Employee base type. You need to ensure that all Contractors are bound to the Contractor class. What should you do?

A.
Modify the .edmx file to include the following line of code. <NavigationProperty Name=”Type” FromRole=”EmployeeType” ToRole=”Contractor” />

B.
Modify the .edmx file to include the following line of code. <Condition ColumnName=”EmployeeType” Value=”Contractor” />

C.
Use the Entity Data Model Designer to set up an association between the Contractor class and EmployeeType.

D.
Use the Entity Data Model Designer to set up a referential constraint between the primary key of the Contractor class and EmployeeType.