Given a paragraph about movies, and a set of conversational question answers about the paragraph, generate a relevant question to the topic of the paragraph. The paragraph has the prefix 'CONTEXT:'. Each conversation question has a prefix 'Q:' followed by the answer prefix 'A:'.
One example: CONTEXT: The balance of power had shifted considerably since the first set of quotes. King Joffrey is dead, and his younger brother Tommen is now king. Unlike his wild card of an elder brother, Tommen is gentler and more prone to manipulation by his new bride. The Lannisters impeccable image has also been shattered. They failed to prevent the assassination of their king in the midst of his own wedding day, and the suspected assassin is the king's Lannister uncle. Not only do they look incompetent, they are divided among themselves. On the other hand, the Tyrells' situation is much stronger now. Tommen is already wrapped around Margaery's pretty little finger, and she knows that the assassination was orchestrated in part by her own family. In Margaery's eyes, the Lannisters look disoriented and lost. Putting on a show trial for one of their own, whom she knows is innocent of any wrongdoing. Whatever power Cersei held over Margaery has now been diminished. <sep> Q: What was Margaery's motivation to call Cersei 'sister' again? A: Whatever power Cersei held over Margaery has now been diminished.
Solution is here: Why has it been diminished?
Explanation: The question is valid since it is on the same topic and a follow-up of the previous answer in the conversation. The question asks about the reason why the power held over Margaery by Cersei have diminished.

Now, solve this: CONTEXT: It is not explained, but we can theorize. We don't know when he rented those books. He might have done so before buying his own (to ensure he indeed should buy them), or because the books weren't easy (or cheap) to purchase. Also remember that instead of renting books on a subject he is well versed in, he probably became well versed on the subject thanks to renting those books. Finally, despite those books in his apartment, IIRC we are never told what those books are about. They might have had nothing to do with the seven deadly sins (John Doe wanted to avoid having incriminating evidence on his home, perhaps?), and thus all of his knowledge came from renting the books in the library. The books in his house might have been educational on a ton of other subjects or philosophies. Also keep in mind, the Internet still wasn't a thing back then. And books such as the ones mentioned (on bondage, homicide, or by Italian Dominican friars) might have not been easily found in your regular old book store. Finally, you can also claim that he rented them to make the plot move along, as this was their main lead. <sep> Q: Why did John Doe need to check out books at a public library? A: It is not explained, but we can theorize
Solution:
What is your theory?