<Style x:Key="HorizontalRadioButtonList" TargetType="{x:Type ListBox}">
<Setter Property="Background" Value="Transparent"/>
<Setter Property="ItemsPanel">
<Setter.Value>
<ItemsPanelTemplate>
<VirtualizingStackPanel Background="Transparent" Orientation="Horizontal"/>
</ItemsPanelTemplate>
</Setter.Value>
</Setter>
<Setter Property="ItemContainerStyle">
<Setter.Value>
<Style TargetType="{x:Type ListBoxItem}" >
<Setter Property="Margin" Value="5" />
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type ListBoxItem}">
<Border BorderThickness="0" Background="Transparent">
<RadioButton Focusable="False"
IsHitTestVisible="False"
IsChecked="{TemplateBinding IsSelected}">
<ContentPresenter />
</RadioButton>
</Border>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</Setter.Value>
</Setter>
<Setter Property="Control.Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type ListBox}">
<Border BorderThickness="0" Padding="0" BorderBrush="Transparent"
Background="Transparent" Name="Bd" SnapsToDevicePixels="True">
<ItemsPresenter SnapsToDevicePixels="{TemplateBinding
UIElement.SnapsToDevicePixels}" />
</Border>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
<ListBox Name="lbAchieved"
Style="{StaticResource HorizontalRadioButtonList}"
SelectedValue="{Binding Path=IsAchieved, Converter={StaticResource
nullableBooleanConverter}}"
SelectedValuePath="Tag">
<ListBoxItem Tag="True">Yes</ListBoxItem>
<ListBoxItem Tag="False">No</ListBoxItem>
</ListBox>