在窗体中添加一个通用对话框，其名称为CommonDialog1，然后添加一个命令按钮。要求单击命令按钮时，打开一个保存文件的通用对话框。该窗口的标题为“打开”，在文件类型框中显示的是Text Files(*.txt)。则能够满足上述要求的程序是

A．Private Sub Command1_Click() CommonDialog1. Flags=cdloFNHideReadonly CommonDialog Filter="AllFiles(*.*)|*.*|TextFiles"&_ "(*.tx|*.txt|BatchFiles(*.ba|*.bat" CommonDialog1.FilterIndex=1 CommonDialog1.ShowOpen MsgBox CommonDialog1.FileName End Sub
B．Private Sub Command1_Click() CommonDialog1. Flags=cdloFNHideReadonly CommonDialog1. Filter="AllFiles(*.*)|*.*|TextFiles"&_ "(*.tx|*.txt|BatchFiles(*.ba|*.bat" CommonDialog1. FilterIndex=2 CommonDialog1. ShowOpen MsgBox CommonDialog1. FileName End Sub
C．Private Sub Command1_Click() CommonDialog1. Flags=cdloFNHideReadonly CommonDialog1. Filter="AllFiles(*.*)|*.*|TextFdes"&_ "(*.tx|*.txt|BatchFiles(*.ba|*.bat" CommonDialog1.FilterIndex=1 CommonDialog1.ShowSave MsgBox CommonDialog1.FileName End Sub
D．Private Sub Command1_Click() CommonDialog1. Flags=edloFNHideReadonly CommonDialog1. Filter="AllFiles(*.*)|*.*|TextFiles"&_ "(*.tx|*.txt|BatchFiles(*.ba|*.bat" CommonDialog1.Filterlndex=2 CommonDialog1.ShowSave MsgBox CommonDialog1.FileName End Sub