The Freezing Point of Seawater Is About -1 $\circ$ CIf Seawater Is an Aqueous Solution of Sodium Chloride,calculate the Seawater

The freezing point of seawater is about -1.85 ^$\circ$ C.If seawater is an aqueous solution of sodium chloride,calculate the molality of seawater.The k_f for water is 1.86 K/m.

A) 1.99 m
B) 0.995 m
C) 3.44 m
D) 3.70 m
E) 0.497 m