The Reaction Between Nitrogen Dioxide and Carbon Monoxide Is Thought $\rightarrow$

The reaction between nitrogen dioxide and carbon monoxide is thought to occur by the mechanism
2NO₂(g $\rightarrow$ NO₃(g) + NO(g)
K₁,Slow
NO₃(g) + CO(g) $\rightarrow$ NO₂(g) + CO₂(g)
K₂,Fast
The rate law for this mechanism is

A) rate = k₁k₂[NO₂]²[CO].
B) rate = (k₁/k₂) [NO₂]²[CO].
C) rate = k₁[NO₃][NO].
D) rate = k₂[NO₃][CO].
E) rate = k₁[NO₂]².