Answer :
Dramatic irony is when the reader/audience knows something that the actor/character does not. At this point in time, we know that Macbeth is behind the death of King Duncan. Banquo at this point assumes the same thing.
it would be verbal irony because it makes the play more tragic because if the reader understands the irony of what the character us saying, then the reader can see the true nature & intentions of the character
