The deliberate suavity of Dev's behaviour made the emotions of the audience volatile.

Answer: Option B

Suavity : the quality of being suave in manner.
Politeness : behaviour that is respectful and considerate of other people.
Impetuosity : liable to act without consideration; rash.
Stupidity : behaviour that shows a lack of good sense or judgement.
Pleasant : giving a sense of happy satisfaction or enjoyment.

Antonym of Suavity is Impetuosity