Which sentence combination uses a subordinating clause

Which best expresses the irony present in this passage?

"first of all, how could they mistake a man for a sasquatch? " which best explains the purpose of this question (from review 2)? a) to illustrate how much the book uses humor b) to show how unbelievable parts of the story are c) to convince the reader that the novel is poorly written d) to highlight the differences between the characters in the novel

What is wrong with they follow citation of a book with two authors