Four words have been given, out of which three are alike in some manner and one is different. Select the word that is different.

Tranquillity

Except Tranquility all are synonyms of each other

Contention , Turmoil , Agitation all are synonyms of each other

Tranquility is the antonym

Contention - heated disagreement

Agitation - disturbance

Turmoil - confusion ,

Tranquility - calm