Proctor believes that Abigail accuses Elizabeth of witchcraft because:

Proctor's Belief in Abigail's Accusation

Proctor's Belief: Proctor believes that Abigail accuses Elizabeth of witchcraft because she seeks revenge on her for her husband's affair.

Final answer:

Abigail accuses Elizabeth of witchcraft because she seeks revenge on her for her husband's affair.

Explanation:

Abigail is believed to accuse Elizabeth of witchcraft because she seeks revenge on Elizabeth. In the Salem witch trials, personal disputes and grudges often led to false accusations. In the case of Abigail and Elizabeth, Abigail resents Elizabeth because Elizabeth's husband, John Proctor, had an affair with Abigail. Accusing Elizabeth of witchcraft provides Abigail with a way to get rid of her and take her place in the family.