In Arthur Miller's The Crucible, act 2, Abigail has convinced the town that she can identify witches and has mentioned the name of Elizabeth as one of those who practice witchcraft. Elizabeth is John Proctor's (Abigail's love interest) wife. After questioning Mary over that day's events in Salem, she reveals that Elizabeth's name has been mentioned, and she (Mary) defended her. Elizabeth then understood that, although Mary was not able to reveal who had made the accusation, Abigail had mentioned her in order to take her place in Proctor's life. After telling John about her theory of she wanting her [Elizabeth] death in order to take the place of John's wife, in lines 471-474 she tells John that she must go and talk Abigail out of it, as she is doing these things because of the promise he made to her in bed.
Therefore, your best answer is Abigail.