窗体上有一个名称为Text1的文本框和一个名称为Command1的命令按钮。要求程序运行时，单击命令按钮，就可以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文件原有内容之后。下面能够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