运行下列程序:Private Sub Command1_Click( )s$ = "abcdefabcdefabcdef"k = InStr(

运行下列程序：

Private Sub Command1_Click( )

s$ = "abcdefabcdefabcdef"

k = InStr(s$, "c")

Do While k > 0

n = n + 1

s$ = Mid(s$, k + 1)

k = InStr(s$, "c")

Loop

Print n

End Sub

单击Command1命令按钮后，则在窗体上显示的结果是( )。

A.1

B.2

C.3

D.4