Answer: D) irony.
Step-by-step explanation: an irony is a state of affairs or an event that seems contrary to what one expects and it often has an amusing result. So, from the given options, the literary device that the author is using when he makes a forceful contrast between expectations (that can be the ones of the characters or the audience) and reality (what really happens), creating a surprise ending for the readers, is the corresponding to option D: irony.