求解答-句子结构

Unlike the original National Museum of Science and Technology in Italy, where the models are encased in glass or operated only by staff members, the Virtual Leonardo Project, an online version of the museum, encourages visitors to "touch" each exhibit, which thereby activates the animated functions of the piece.  

(A) exhibit, which thereby activates

(B) exhibit, in turn an activation of

(C) exhibit, and it will activate

(D) exhibit and thereby activate(D)

(E) exhibit which, as a result, activates

这道题AE解释是 which无先行词， 是不是touch the exhibit 才能activate吗，而不是exhibit activate？

解释：AE选项的which没有先行词，B选项后面的句子没有谓语动词。D选项是省略了thereby后面的to，和to touch平行的。