C-14-Q054mediumsingle_mcqIn △ABC\triangle ABC△ABC, medians ADADAD, BEBEBE meet at GGG. A line through GGG parallel to DEDEDE meets ACACAC at FFF. Then AC=?AC = ?AC=?a3EF3 EF3EFb4EF4 EF4EFc6EF6 EF6EF