As was discussed before．it was not until the 19th century that the newspaper became the dominant pre-electronic medium．

A. 正如以前谈过，直到19世纪报纸才成为电子时代以前的主导媒体。
B. 正如以前谈过，直到19世纪报纸还没成为电子时代以前的主导媒体。
C. 正如以前谈过，19世纪后报纸才成为电子时代以前的主导媒体。
D. 正如以前谈过，直到19世纪报纸才占领电子时代以前的媒体。