Who is the only living child of the Putnams involved in the witchcraft accusations?

The correct choice is Ruth Putnam, as she is the only living child of Thomas and Ann Putnam who is involved in the witchcraft accusations within "The Crucible." Throughout the play, Ruth is depicted as being in a state of affliction and plays a crucial role in the unfolding events. Her condition leads her parents to suspect witchcraft, aligning with the broader themes of hysteria and accusation that sweep through Salem.

Ann Putnam, while deeply affected by the loss of her other children, is not a child herself and therefore cannot be considered among the living children implicated in the witchcraft trials. Betty Parris, though involved in the accusations, is the daughter of Reverend Parris, not a Putnam. Abigail Williams, while a significant character in the play, is actually the niece of Reverend Parris and not related to the Putnams at all. Thus, Ruth Putnam stands out as the only living child of the Putnams linked to the witchcraft hysteria, highlighting the tragic consequences of the Salem witch trials for families involved.