The sentence from paragraph 19 of Passage 2 that highlights the idea that Stine strives for readers to interact with the story is:
"In the Goosebumps books, I did as little characterization as possible..." -because when you are writing scary books, you want the kid reading it to feel like they are experiencing the story."
Characterization refers to the manner in which a writer presents the actors in a story. He could clearly state their attributes or allow readers to deduce these based on their actions or thoughts.
In the third option above, we find that the author's reason for using little characterization was because he wanted the readers to feel like they are experiencing the story. So, option C is right.
Learn more about characterization here:
https://brainly.com/question/1393329