What action does Proctor take that is a turning point for his character?

Proctor's decision to confront Abigail and expose her lies serves as a significant turning point for his character as it represents his move towards moral integrity and personal redemption. Throughout the play, Proctor struggles with guilt and the weight of his past actions, especially his affair with Abigail. By standing up to her and revealing the truth, he challenges the foundation of the hysteria gripping Salem and takes a stand against the manipulation and deceit that Abigail has perpetrated.

This moment is crucial not only for Proctor's character development but also for the broader narrative of the play. It illustrates his transition from a man burdened by shame to one who is willing to fight for what is right, despite the risks involved. It highlights his desire to reclaim his honor and act in accordance with his principles, distinguishing him from others who remain complicit in the lies and fear that define the witch trials.

The other options do not encapsulate this transformation in the same way. Admitting to being a witch or deciding to leave Salem reflects a defeat or escape from responsibility rather than an active choice to confront and rectify the situation. Publicly denouncing the trials, while significant, comes after his confrontation with Abigail, which is the initial catalyst for his commitment to truth and justice.