[单项选择题] 编写如下事件过程: Private Sub Form_MouseDown(Button AS Integer,Shift AS Integer,_ X As Single,Y As Single) If Shift=6 And Button=2 Then Print,"PC" End If End Sub 程序运行后,为了在窗体上输出“PC”,应执行的操作为
A.同时按下Shift键和鼠标左键
B.同时按下Ctrl,Alt键和鼠标右键
C.同时按下Shift键和鼠标右键
D.同时按下Ctrl,Alt键和鼠标左键