The Gas-Phase Reaction CH₃NC $\to$ CH₃CN Has Been Studied in a Closed Vessel,and the Rate

The gas-phase reaction CH₃NC $\to$ CH₃CN has been studied in a closed vessel,and the rate equation was found to be: rate = - $\Delta$ [CH₃NC]/ $\Delta$ t = k[CH₃NC].Which one of the following actions is least likely to cause a change in the rate of the reaction?

A) lowering the temperature
B) adding a catalyst
C) using a larger initial amount of CH₃NC in the same vessel
D) using a bigger vessel,but the same initial amount of CH₃NC
E) continuously removing CH₃CN as it is formed