You use Microsoft .NET Framework 4 to create a Windows Presentation Foundation (WPF) application.
The application contains a window as shown in the following exhibit.
You need to define a DockPanel control that fits the window.
Which code fragment should you use?

A.
<DockPanel>
<Button Content=”Left”/>
<Button Content=”Top” DockPanel.Dock=”Top”/>
<Button Content=”Bottom” DockPanel.Dock=”Bottom”/>
<Button Content=”Center”/>
</DockPanel>

B.
<DockPanel>
<Button Content=”Top” DockPanel.Dock=”Top”/>
<Button Content=”Bottom” DockPanel.Dock=”Bottom”/>
<Button Content=”Left”/>
<Button Content=”Center”/>
</DockPanel>

C.
<DockPanel>
<Button Content=”Left”/>
<Button Content=”Top” DockPanel.Dock=”Top”/>
<Button Content=”Center”/>
<Button Content=”Bottom” DockPanel.Dock=”Bottom”/>
</DockPanel>

D.
<DockPanel>
<Button Content=”Top” DockPanel.Dock=”Top”/>
<Button Content=”Left”/>
<Button Content=”Center”/>
<Button Content=”Bottom” DockPanel.Dock=”Bottom”/>
</DockPanel>