At Elevated Temperatures, Methylisonitrile (CH₃NC) Isomerizes to Acetonitrile (CH₃CN)

At elevated temperatures, methylisonitrile (CH₃NC) isomerizes to acetonitrile (CH₃CN) :
CH₃NC (g) → CH₃3CN (g)
The reaction is first order in methylisonitrile. The attached graph shows data for the reaction obtained at 198.9°C.

The rate constant for the reaction is s^{- 1}.

A) +5.2 × 10^{- 5}
B) +6.2
C) +1.9 × 10⁴
D) - 5.2 × 10^{- 5}
E) - 1.9 × 10⁴