单项选择题

在窗体上画一个命令按钮,然后编写如下事件过程:
Option Base 1
Private Sub Command1 Click()
Dim a
a=Array(1, 2, 3, 4)
j = 1
For i = 4 To 1 Step -1
s = s + a(i)* j
i = j * 10
Next i
Print s
End Sub
运行上面的程序,单击命令按钮,其输出结果为

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