Situational irony. The definition of situational irony is “the contrast between what a reader or character expects and what actually exists or happens.
"I have a dream that one day even the state of Mississippi, a state sweltering with the heat of injustice, sweltering with the heat of oppression, will be transformed into an oasis of freedom and injustice." is one example of a synecdoche
The answer is B.
One thing that will help with these kinds of questions is saying each out load to see if they sound right or not