某Visual Basic程序如下:
Private Sub Command1_Click()
Dim i As Integer, sum As Integer
sum = 0
For i = 10 To 2 Step -2
sum = sum + i
Next i
Text1.Text = Str(sum)
End Sub
运行程序,单击命令按钮Command1后弹出如图所示的出错信息提示,此时程序正执行的语句是( )

A.Sum = 0 | B.For i = 10 To 2 Step -2 |
C.sum = sum + i | D.Text1.Text = Str(sum) |