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.

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.
who are the liars in pretty little liars