Irony is a figure of speech in which the result of an action is expected to be totally opposite to the normal result. In this particular case , answer C is trying to make focus that the mayor is a fool and SUDDENLY he took a smart decision.
if you are with k12 i just did the test and the answer is b) Master Hauchecorne, who is often deceitful, breaks down when people don't believe he is telling the truth.
