单项选择题

在窗体上画一个命令按钮,然后编写如下事件过程:   Private Sub Command1_Click( )    Dim m As Integer,n As Integer,p As Integer    m=3:n=5:p=O    Call Y(m,n,p)    Print Str(p)   End Sub   Sub Y(ByVal i As Integer,ByVal j As Integer,k As Integer)    k=i + j   End Sub   程序运行后,如果单击命令按钮,则在窗体上显示的内容是( )。

A.4
B.6
C.8
D.10