The Reaction CH₃- N≡C - CH₃- C≡N

The reaction
CH₃- N≡C - CH₃- C≡N
Is a first- order reaction. At 230.3°C, k = 6.29 × 10^{- 4} s^{- 1}. If [CH₃- N≡C] is 1.00 × 10^{- 3} initially, [CH₃- N≡C] is after 1.000 × 10³ s.

A) 2.34 × 10^{- 4}
B) 4.27 × 10^{- 3}
C) 1.00 × 10^{- 6}
D) 5.33 × 10^{- 4}
E) 1.88 × 10^{- 3}