单项选择题

下列程序运行后的输出结果是______。
Private Sub f(k,s)
s = 1
for j = 1 To k
s=s*j
Next j
End Sub
Private Sub Command1_ Click ()
Sum = 0
for i = 1 To 3
Call f(i, s)
Sum = Sum + s
Next i
Print Sum
End Sub

A.0
B.3
C.6
D.9