At Elevated Temperatures,methylisonitrile (CH₃NC)isomerizes to Acetonitrile (CH₃CN): CH₃NC (G)→ CH₃CN

At elevated temperatures,methylisonitrile (CH₃NC) isomerizes to acetonitrile (CH₃CN) : CH₃NC (g) → CH₃CN (g)
At the start of an experiment,there are 0.200 mol of reactant and 0 mol of product in the reaction vessel.After 25 min,0.121 mol of reactant (CH₃NC) remain.There are ________ mol of product (CH₃CN) in the reaction vessel.

A) 0.022
B) 0.121
C) 0.200
D) 0.321
E) 0.079