The item that does not belong in the group is "Banquet" because the other items—King Duncan, Ghost, and Guilt—are directly related to the themes of death and the psychological consequences of murder in Shakespeare's "Macbeth."
King Duncan represents the tragic victim of Macbeth's ambition, and his murder is the catalyst for the chaos that ensues. After Duncan's death, the appearance of his ghost at the banquet serves as a haunting reminder of Macbeth's guilt and the moral consequences of his actions. The ghost's presence deeply unsettles Macbeth, as he exclaims, "Thou canst not say I did it; never shake thy gory locks at me," indicating how guilt manifests itself and torments him. This overwhelming guilt ultimately leads to Macbeth's unraveling, illustrating how the psychological burden weighs heavily on the characters who commit heinous acts.
Thus, while the banquet may represent a social gathering filled with feasting and celebration, it stands apart from the dark themes associated with the other three elements, which all focus on the consequences of ambition, betrayal, and the haunting effects of guilt.