You are designing a Windows Phone 7 application that consists of a single XAML page. A rectangle that is hidden within the page appears as a result of a user action. You need to ensure that the rectangle is hidden and the application remains open when the user presses the Back key. Which code segment should you use?

A.
Protected Overrides Sub OnBackKeyPress(
ByVal e As System.ComponentModel.CancelEventArgs)
If popUp.Visibility =
System.Windows.Visibility.Visible Then

B.
Cancel = True
popUp.Visibility = System.Windows.Visibility.Collapsed End If
End Sub

C.
Sub NavigationService_Navigating(ByVal sender As Object, ByVal e As NavigatingCancelEventArgs)
If (e.NavigationMode = NavigationMode.Back) Then

D.
Cancel = True
popUp.Visibility = System.Windows.Visibility.Collapsed End If
End Sub

E.
Protected Overrides Sub OnNavigatingFrom(
ByVal e As NavigatingCancelEventArgs)
MyBase.OnNavigatingFrom(e)

F.
Cancel = True
popUp.Visibility = System.Windows.Visibility.Collapsed End Sub

G.
Protected Overrides Sub OnNavigatedFrom(
ByVal e As NavigationEventArgs)
MyBase.OnNavigatedFrom(e)
popUp.Visibility = System.Windows.Visibility.Collapsed End Sub