有如下VB程序段: s = Text1.Text
ans = "": k =4
i = k - 1: j = k + 1: n = Len(s)
Do While k > 0
If Mid(s ,i,1) = Mid(s, j, 1) Then
ans = ans + Mid(s, i,1): k = k - 1
End If
i = (n + i - 2) Mod n + 1
j = j Mod n+1
Loop
Label1.Caption=ans
在文本框Text1中输入“banana”,执行程序后,标签Label1中显示的内容是( )