In this task you will be given an answer to a question. You need to generate a question. The answer given should be a correct answer for the generated question.
Example: This list contains the top 25 accounts with the most followers on the social photo-sharing platform Instagram. As of May 2018, the most followed user is Instagram's own account, with over 235 million followers. Selena Gomez is the most followed individual, with over 137 million followers. Ten accounts have exceeded 100 million followers on the site.
Example solution: who has the maximum number of followers on instagram
Example explanation: The answer is talking about the Instagram accounts that have the most followers. The question asking about the maximum number of followers. So this is a good example.

Problem: Set in the small suburban town of Rosewood, Pennsylvania (not far from Philadelphia), the series follows the lives of five girls: Spencer Hastings, Alison DiLaurentis, Aria Montgomery, Hanna Marin and Emily Fields, whose clique falls apart after the leader of the group, Alison, goes missing. One year later, the remaining estranged friends are reunited as they begin receiving messages from a mysterious villain named 'A' or 'A.D.', who threatens and tortures them for the mistakes they have made before and after Alison's death. At first, they think it is Alison herself, but after her body is found, the girls realize that someone else is planning on ruining their lives.
Solution: who are the liars in pretty little liars