单项选择题

在窗体上画一个命令按钮(其NAME属性为Command1),然后编写如下代码:   Option Base 1   Private Sub Command1_Click()    Dim a    s = 0    a = Array(1,2,3,4);j = 1    For i = 4 To 1 Step -1     s = s + a(i) * j     j = j * 10    Next i    Print s   End Sub   运行上面的程序,单击命令按钮,其输出结果是( )。

A.4321
B.1234
C.34
D.12