WPF - How do I make the RadioButtons generated by the DataTemplate mutually exclusive?

In one of the applications I am building, I need to create a survey for users. The relevant classes related to my question are as follows:

 Survey (string Description, List<Questions> Questions, QuestionTypes Type)
 Question (string Description, List<Choice> Choices)
 Choice (string Description)
 enum QuestionTypes {MultipleChoicesOneAnswer, MultipleChoicesMultipleAnswers}

      

        
        
        
      

    

In a ListBox, I want to display each question on its own border and the choices available for each question. For example:
1) How many hours a day?
[] 21
[] 22
[] 23
[] 24

The parentheses above represent a radio button (if the question type is "MultipleChoicesOneAnswer") or a checkbox (for questions like "MultipleChoicesMultipleAnswers")

I am using the following templates:

<DataTemplate x:Key="MultipleChoicesOneAnswerTemplate" DataType="{x:Type local:Choice}">
   <RadioButton Content="{Binding Description}" Foreground="Blue"  />
</DataTemplate>


<DataTemplate x:Key="QuestionTemplate" DataType="{x:Type local:Question}">
   <DockPanel>
      <StackPanel Orientation="Horizontal" DockPanel.Dock="Top">
         <TextBlock Text="{Binding SortingIndex}" />
         <TextBlock Text=")" />
         <TextBlock Text="{Binding Description}" Margin="5,0,0,0"/>
      </StackPanel>
      <ListBox ItemTemplate="{StaticResource MultipleChoicesOneAnswerTemplate}" ItemsSource="{Binding Choices}"/>
   </DockPanel>
</DataTemplate>

      

        
        
        
      

    

With these templates, I get a RadioButton for each selection, but they are not mutually exclusive for each question.

My questions for you:

 1. What can I do to make the RadioButtons generated by the template mutually exclusive?
 2. How do I navigate to the entry in my model that the user has selected?

Many thanks for your help.

UPDATE: Following csunwold's suggestion, it worked using GroupName, but it looks a bit like a hack as I had to override ToString () in the Question class, spitting out the description, and GroupName = "{Binding Question}".

Anyone have any suggestions?