Verbal | "WHICH" Tragedy

I learnt and used WHICH as ( , which) and using this means "which" is modifying the noun just before it

But in this example

Given its authoritative coverage of other science topics, the textbook's chapter on genetics is surprisingly tentative, which leads one to doubt the author's scholarship in that particular area.

A) the textbook's chapter on genetics is surprisingly tentative, which leads
B) the chapter of the textbook on genetics is surprisingly tentative, leading
C) the