单选题 执行下列程序后，鼠标单击窗体，输出结果为( )。
Private Sub Form_Click()
Print "Click";
End Sub
Private Sub Form_MouseDown(Button As Integer, Shift
As Integer,X As Single,Y As Single)
Print "Down"
End Sub
Private Sub Form_MouseUp(Button As Integer, Shift_
As Integer,X As Single,Y As Single)
Print "Up"
End Sub
A) DownUpClick B) ClickDownUp
C) DownClickUp D) UpDownClick