Which is an example of irony in Macbeth?

A. Macbeth is unable to say "amen" after he hears King Duncan's guards praying in their sleep.
B. Lady Macbeth returns the bloody dagger to King Duncan's room after Macbeth is too upset to do it himself.
C. The three witches make the prediction that Macbeth will someday be both thane of Cawdor and king.
D. King Duncan thinks Macbeth is a good and virtuous man, when in reality, Macbeth is plotting his murder.

Question

Which is an example of irony in Macbeth?

 		A.	Macbeth is unable to say "amen" after he hears King Duncan's guards praying in their sleep.
 		B.	Lady Macbeth returns the bloody dagger to King Duncan's room after Macbeth is too upset to do it himself.
 		C.	The three witches make the prediction that Macbeth will someday be both thane of Cawdor and king.
 		D.	King Duncan thinks Macbeth is a good and virtuous man, when in reality, Macbeth is plotting his murder.