窗体上有一个名称为Text1的文本框和—个名称为Command1的命令按钮。要求程序运行时,单击命令按钮,就可把文本框中的内容写到文件out.txt中,每次写入的内容附加到原有内容之后。下面能够正确实现上述功能的程序是______。 A.Private Sub Command1_Click() Open 'out.txt' For Input As#1 Print #1,Text1.Text Close #1 End Sub B.Private Sub Command1_Click() Open 'out.txt' For Output AS #1 Print #1,Text1.Text Close #1 End Sub C.Private Sub Command1_Click() Open 'out.txt' For Append As #1 Print #1,Text1.Text Close #1 End Sub D.Private Sub Command1_Click() Open 'out.txt' For Random As #1 Print #1,Text1.Text Close #1 End Sub