单选题
设有下面程序代码：
Private Sub Command1_Click()
Dim str As String，ch As String
str=”Visual Basic Programming”：ch=”a”
n=fun(ch,str)：Print str,n
End Sub
Private Function fun(ch As String，str As String)As Integer
Dim strbuf As String，c As String，n As Integer
For k=1 To Len(str)
c=Mid$(str,k，1)
Ifc<>ch Then
strbuf=strbuf&c
Else
strbuf=strbuf&UCase(c)：n=n+1
End If
Next k
str=strbuf：fun=n
End Function
程序运行时的输出是