'Obstreperous' means unruly, difficult to control, or aggressively resisting authority or control. It describes someone who is noisy, defiant, and hard to manage. Option C 'unruly' is the correct synonym. The distractors 'submissive' and 'obedient' are actually antonyms (opposites) of obstreperous. 'Violent' is too strong - obstreperous is about being difficult/uncontrollable, not necessarily violent.