单项选择题

有如下函数过程:
Function gys(ByVal x As Integer,ByVal y As Integer) As Integer
Do While y<>0
reminder = x Mod y
x=y
y=reminder
Loop
gys=x
End Function
以下是调用该函数的事件过程,该程序的运行结果是______。
Private Sub Command7_Click()
Dim s As Integer
Dim b As Integer
a=100
b=25
x=gys(a,b)
Print x
End Sub

A.0
B.25
C.50
D.100