The Carbon Cycle Characterizes the Cyclic Transformations of the Element

The carbon cycle characterizes the cyclic transformations of the element carbon through the environment and biomass.Some of the important species in this cycle are CO₂,CO₃^2-,C₆H₁₂O₆,and CH₄.Complete oxidation by O₂ would lead to the largest change in oxidation number for which of the following?

A) CO₂
B) CO₃^2-
C) C₆H₁₂O₆
D) CH₄
E) CO₂ and CO₃^2- are equivalent in this regard.