Answer: The right answer is the D) The noose.
Explanation: Although the railroad tracks (since the protagonists of this story were standing in a railroad bridge twenty feet above the ground), the cannon (which was pointing towards the bridge) and the wooden planks (where the prisoner and his executioners were standing) could be also arguably interpreted as motifs that represent being trapped, since they were meant to prevent Peyton Farquhar from escaping alive, the noose is certainly the more obvious, since, tightened around his neck and attached to a timber above his head, it limited his movements and inevitably subjected him to his captors' will.
