单项选择题

有如下程序:
Private Sub Command1_Click()
Dim a As Single
Dim b As Single
a=5: b=4
Call Sub1(a,b)
End Sub
Sub Sub1(x As Single,y As Single)
t=X
X=t\y
y=t Mod y
End Sub
在运行上述程序后,a和b的值分别为( )。

A) 0 0
B) 1 1
C) 2 2
D) 1 2