Answer:
b). To represent evil forces
The role of the witches in Macbeth is primarily to represent evil forces. They are the ones who initially prophesy that Macbeth will become king and thus set in motion the events that lead to his downfall. The witches are often seen as a symbol of temptation and the corrupting influence of power. They also serve to create a sense of foreboding and mystery throughout the play, as their supernatural abilities are both fascinating and unsettling to the other characters. While the witches do not directly advise Macbeth, their presence and prophecies have a significant impact on his decisions and actions. They do not provide comic relief, as their scenes are typically eerie and ominous.