You need to create a query expression to display all of the grades for students whose first name is "John" How should you build the expression?

You are developing an application in Visual Studio 2012 to display student information. The
application contains the following Entity Framework model.

The application contains a WCF data service named DirectoryService.svc.
You need to create a query expression to display all of the grades for students whose first
name is “John”
How should you build the expression?

A.
http://localhost:54946/DirectoryService.svc/Students?$filter=FirstName eq ‘John’
&$expand=Grades

B.
http://localhost:54946/DirectoryService.svc/Students?$filter=FirstName eq ‘John’/Grades

C.
http://localhost:54946/DirectoryService.svc/Students?$filter=FirstName = ‘John’
&$expand=Grades

D.
http://localhost:54946/DirectoryService.svc/Grades/Students?$filter=FirstName eq ‘John’