What does the apparition of the helmeted head foreshadow in this excerpt?

"Macbeth! Macbeth! Macbeth! beware Macduff;
Beware the thane of Fife."

A.) a child not born of woman

B.) Banquo's return from the dead

C.) Macbeth's descent into madness

D.) the battle between Macbeth and Macduff