一道助词补出题，请大家指点一下我！！！

kittyocathy

Many teenagers undergo stress, but results of a recent study indicate that the patterns of stress that
girls experience are more likely to result in depression than are those that boys experience.

(A) are those that boys experience
(B) what boys experience
(C) boys' experience would
(D) boys' stress patterns do
这个are为什么要补充呢？ 正确答案A

AlohaDJ

The patterns of stress (that girls experience) are more likely to do than those (that boys experience) are (likely to do)....

句中的those指代对应前面的patterns of stress。