GWD-20 31 句子结构有问题

Q31:

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.

1. exhibit, which thereby activates
2. exhibit, in turn an activation of
3. exhibit, and it will activate
4. exhibit and thereby activate
5. exhibit which, as a result, activates

这道题答案选D，但是根据句意，后面的activate的逻辑主语应该是“Virtual Leonardo Project, an online version of the museum, encourages visitors to “touch” each exhibit"这件事，而不是“the Virtual Leonardo Project",这样看来应该用activating，但是没有这个选项，疑惑呀！！！