有如下程序：Private Sub Commandl_Click()Dim a As SingleDim b As Singlea=2：b=4Call CS(a，b)End SubSub CS(x As Single，y As Single)t=Xx=t yy=t Mod yEnd Sub程序运行后，单击命令按钮，a和b的值分别为( )。
A．Dim pict[3,4]As Integer
B．Dim pict(3，4)As Integer
C．Dim pict[3．4]As Integer
D．Dim pict(3：4)As Integer．