This System of Chemicals $\mathrm { II } _ { 2 } \mathrm { CO } _ { 3 } ? \mathrm { II } ^ { + } + \mathrm { IICO } _ { 3 }^-$

This system of chemicals, $\mathrm { II } _ { 2 } \mathrm { CO } _ { 3 } ? \mathrm { II } ^ { + } + \mathrm { IICO } _ { 3 }^-$ ,act as a buffer in the blood.If hydrogen ions are added to blood which of the following reactions would occur?

A) $\mathrm { H } ^ { + } + \mathrm { HCO } _ { 3 } { } ^ { - } \longrightarrow \mathrm { H } _ { 2 } \mathrm { CO } _ { 3 }$
B) $\mathrm { OH }^- + \mathrm { H } _ { 2 } \mathrm { CO } _ { 3 } \longrightarrow \mathrm { HCO } _ { 3 } { } ^ { - } + \mathrm { H } _ { 2 } \mathrm { O }$