Which situation is most clearly ironic?

Answer:

C

Explanation:

By definition, irony is a state of affairs or an event that deliberately is contrary to what one expects and is often amusing as a result. A very powerful vampire choosing to not use his power and instead being vegetarian fits this definition. However, A and D, are neither surprising or humorous. B was actually a very common affair between aristocrats and is therefore neither surprising or humorous. This leaves C as the answer.