单项选择题

有如下函数过程:
Function Fun(By Val x As Integer,By Val y As Integer)As Integer
  Do While Y<>0
    reminder=x Mod y
    x=y
    y=reminder
  Loop
  Fun=x
End Function
以下调用函数的事件过程,该程序的运行结果是
Private Sub Command7_Click()
Dim a As Integer,b As Integer
  a=100:b=25
  x=Fun(a,B)
  Print x
End Sub

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