In Macbeth's Act 1 Scene 1, both Banquo and Macbeth wonder (D) whether the prophecy about Banquo is true.
In the Royal Palace, Banquo thinks about the prophecy of the witches. At the beginning of the play, the sisters had foretold that he would become the father of a line of kings, but they had also predicted that Macbeth would become Thane of Cawdor, which immediately came true. For this reason, Macbeth fears he will not have a heir to the throne and also wonders about the possibility of Banquo's line to sit on the throne in his soliloquy, where he confesses to feel threatened by his friend.