单项选择题

假定有以下函数过程:
  Function Fun(S As String) As String
  Dim sl As String
   For i=1 To Len(S)
     s1=UCase (Mid(S,i,1))+s1
   Next i
   Fun=s1
  End Function
则Str2=Fun("abcdefg”)的输出结果为( )。

A.abcdefg
B.ABCDEFG
C.gfedcba
D.GFEDCBA