从所给的四个选项中，选择最合适的一个填入问号处，使之呈现一定的规律性：（）.

A.A

B.B

C.C

D.D

在窗体上画一个名称为、commonDidog1的通用对话框，一个名称为Command1的命令按钮。要求单击命令按钮时,打开一个保存文稿件的通用对话框。该窗口的标题为”Save",缺省文件名为”SaveFile",在“文件类型”栏中显示*.txt,则能够满足上述要求的程序是

A．Private Sub Command1_Click( ) CommonDislog1.FileName="SaveFile" CommonDialog1.Filter="All Files|*.*|(*.tx|*.txt|(*.do|*.doc" CommonDialog1.FUterlndex=2 CommonDialog1.DialogTitle="Save" CommonDi810S1.Action=2 End Sub

B．Pnrate Sub Command1_Click( ) CommonDialog1.FileNamc="SaveFile" CommonDialog1.Filtcr="All Files|*.*|(*.tx|*.txt|(*.do|*.doc" commonDislog1.Filterlndex=1 CommonDialog1.DialogTitle="Save" CommonDialog1.AcUon=2 End Sub

C．Private Sub Command1_C1ick( ) CommonDialog1.FileName="Saven" CommonDislog1.Filter="All Files|*.*I(*.txI*.txt(*.do1*.doc" CommonDislog1.Fiterlndex=2 Commondislog1.DialogTide="SaveFile" CommonDialog1.Action=2 End Sub

D．PnvateSubCommarldl_C1ick( ) CommonDialog1.FUeName="SaveFile" CommonDialog1.Filter="All Files|*.*I(*.tx|*.txt|(*.do|*.doc" CommonDialog1.Filterlndex=1 CommonDialog1.DislogTitle="SaveFile" CommonDialog1.Achon=1 End Sub