Antonym of TURBULENT

Answer: Option C

Turbulent : characterized by conflict, disorder, or confusion; not stable or calm.
Turbid : (of a liquid) cloudy, opaque, or thick with suspended matter.
Violent : using or involving physical force intended to hurt, damage, or kill someone or something.
Steady : firmly fixed, supported, or balanced; not shaking or moving.
Critical : expressing adverse or disapproving comments or judgements.

Antonym of Turbulent is Steady