单项选择题

有如下函数过程:
Function fun1 (ByVal x As Integer, ByVal y As Integer) As Integer
Do While y <> 0
reminder=x Mod y
x=y
y=reminder
Loop
fun1=x
End Function
在下列按钮单击事件中调节器用该函数,则该程序的运行结果是( )。
Private Sub Command1_Click()
Dim a As Integer
Dim b As Integer
a=100
b=25
x=fun1(a, b)
Print x
End Sub

A.0
B.25
C.5O
D.100