Macbeth speaks the following lines to Lady Macbeth: "O! full of scorpions is my mind, dear wife; thou know'st that Banquo and his Fleance lives." - "The Tragedy of Macbeth," William Shakespeare. Read the passage. What does the "scorpions" metaphor mean in this excerpt?

a. Macbeth's thoughts are painful to him.

b. Macbeth is planning to poison someone.

c. Macbeth is planning to consult the witches.

d. Macbeth's thoughts are spurring him to action.