The opposition made a strident demand for putting the bill to vote.

Answer: Option C

Courageous : not deterred by danger or pain; brave.
Brave : ready to face and endure danger or pain; showing courage.
Vociferous : expressing or characterized by vehement opinions; loud and forceful.
Powerful : having great power or strength.
Strident : presenting a point of view, especially a controversial one, in an excessively forceful way.

Synonym of Strident is Vociferous