One Reaction That Occurs in an Automobile Catalytic Converter Is $\rightarrow$

One reaction that occurs in an automobile catalytic converter is the conversion of carbon monoxide to carbon dioxide. How could the rate of this reaction be expressed correctly in terms of the rate at which the concentration of a reactant or product changes?
2CO(g) + O₂(g) $\rightarrow$ 2CO₂(g)

A) Rate = $\Delta$ CO]/ $\Delta$ t
B) Rate = - $\Delta$ [CO]/ $\Delta$ t
C) Rate = $\Delta$ O₂]/ $\Delta$ t
D) Rate = - $\frac { 1 } { 2 }$
$\Delta$ [CO]/ $\Delta$ t
E) Rate = 2 $\Delta$ [CO₂]/ $\Delta$ t