The Elementary Reaction 2NO₂ (G) → 2NO (G) + O₂

The elementary reaction 2NO₂ (g) → 2NO (g) + O₂ (g)
Is second order in NO₂ and the rate constant at 660 K is 5.23 M^-1s^-1. The reaction half-life at this temperature when [NO₂]₀ = 0.45 M is ________ s.

A) 2.4
B) 7.6
C) 0.19
D) 0.13
E) 0.42