XY05-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

请问谁才是activate的主语?是"the Virtual Leonardo Project","exhibit"还是"visitors"?

visitors

The project encourages visitors to touch and thereby activate functions.

我觉得visitors touch exhibit 这件事才是ACTIVATE的主语， 我选C

请问答案是什么啊， 谢谢

支持C it指代“touch” each exhibit