软件开发离不开系统环境资源的支持，其中必要的测试数据属于

A．项目(工程)窗
B．工具箱
C．代码窗口
D．属性窗口

A．Private Sub Form_MouseDown(Button As Integer，Shift As Integer,_X As Single，Y As Single)
　　If Button=2 Then PopupMenu Bs，2
End Sub
B．Private Sub Form_MouseDown(Button As Integer，Shift As Integer,_X As Single，Y As Single)
　　PopupMenu Bs
End Sub
C．Private Sub Form_MouseDown(Button As Integer，Shift As Integer,_X As Single，Y As Single)
　　PopupMenu Bs，0
End Sub
D．Private Sub Form_MouseDown(Button As Integer，Shift As Integer,_X As Single，Y AS Single)
　　If(Button=vbLeftButton)Or(Button=vbRightButton)Then PopupMenu Bs
End Sub