You use Microsoft .NET Framework 4 to create a Windows Presentation Foundation (WPF) application. 
You add a ListBox to show grouped data.  
The ListBox is data-bound to a collection of items. Each item has the Name and State properties. 
You need to ensure that the ListBox meets the following requirements: 
Names grouped by State 
Names sorted in ascending order  
States sorted in descending order 
Which code fragment should you use?（）

You use Microsoft .NET Framework 4 to create a Windows Presentation Foundation (WPF) application. 
You add a ListBox control to the application. The ListBox control is data-bound to an instance of a custom collection class of the Product objects named ProductList. 
You need to ensure that changes to ProductList are automatically reflected in the ListBox control. 
What should you do? （）