感觉it也可以，为什么非要用which呢？

【问】

As a new way of shopping, live-streaming has proved successful, ____ has led more companies to use online influencers to promote their products. 作为一种新的购物方式，直播已经证明是成功的，这使得更多的公司使用在线大V来促销他们的产品。

答案是which，感觉it也可以，二者的区别究竟在哪里？