D. If Macbeth took the crown unjustly
In Banquo's lines he says, " I fear Thou played’st most foully for ’t." He is saying that he worries that Hamlet took the crown illegally. He then goes on to say that everything the witches said was true for Macbeth so hopefully it will be true of him. This eliminates option C. There is no mention of Macbeth killing him. He speaks of his children becoming king but not himself.