单项选择题

在窗体上画一个名称为Command1命令按钮，然后编写如下事件过程： Private Function fun1(n As Integer)As Integer Dim k As Integer If n = 1 Then k = 1 Else k = 1 + fun1(n - 1)* 2 End If fun1 = k End Function Private Sub Command1_Click () Dim m As Integer, x As Integer x = 4 m = fun1 (x) Print m End Sub 程序运行后，单击命令按钮，则窗体上显示的内容是