Consider the Equilibrium Established in the Carbonic Acid-Bicarbonate Buffer System $\mathrm{H}_{2} \mathrm{CO}_{3} \rightarrow \mathrm{HCO} 3-+\mathrm{H}+$

Consider the equilibrium established in the carbonic acid-bicarbonate buffer system, which maintains pH balance in mammalian blood:
$\mathrm{H}_{2} \mathrm{CO}_{3} \rightarrow \mathrm{HCO} 3-+\mathrm{H}+$
During hypoventilation, breathing rate decreases, and therefore elimination of CO₂ during exhalation decreases. How is optimal blood pH maintained when acid levels increase in our blood from hypoventilating?

A) Excess H+ from the acid reacts with H₂CO₃to decrease pH level.
B) Excess H+ from the acid reacts with H₂CO₃to increase pH level.
C) Excess H+ from the acid reacts with H₂CO₃to maintain pH level.
D) Excess H+ from the acid reacts with HCO3- to increase pH level.
E) Excess H+ from the acid reacts with HCO3- to maintain pH level.