One Reaction by Which the Ocean Acts to Remove Carbon $\rightarrow$

One reaction by which the ocean acts to remove carbon from the atmosphere is:

A) CO₂ (g) + H₂O (l) $\rightarrow$ H₂CO₃ (aq) .
B) H₂CO₃ (aq) $\rightarrow$ CO₂ (g) + H₂O (l) .
C) CH₄ (g) + 2 O₂ (g) $\rightarrow$ CO₂ (g) + 2 H₂O (g) .
D) CO₂ (g) + 2 H₂O (g) $\rightarrow$ CH₄ (g) + 2 O₂ (g) .