The best response for what situational irony and dramatic irony have in common is:
They both usually unfold slowly in a story as details emerge and events occur.
Situational irony occurs when there is a discrepancy between what is expected to happen and what actually happens, typically revealed through the unfolding of the plot. Dramatic irony arises when the audience knows something that the characters do not, often building tension and suspense as the details emerge. Both types of irony depend on the progression of the story and the revelation of information over time.