The correct option is A Carbonic anhydrase
Bicarbonates
The largest fraction of transportation of carbon dioxide in our body takes place in the form of bicarbonate ions.
When carbon dioxide diffuses into RBCs at the tissues, it combines with water to form carbonic acid.
Since carbonic acid is unstable , it quickly dissociates into bicarbonate ions and hydrogen ions. When bicarbonate ions from RBC moves into plasma, it changes the ionic balance between plasma and RBC. To restore the ionic balance chloride ions from plasma diffuse into RBC.
Carbonic anhydrase
Although this reaction occurs in plasma. It is thousand of times faster in RBC because they contain the enzyme carbonic anhydrase that reversibly catalyses the conversion of carbon dioxide and water to carbonic acid.
Final answer
(C) Carbonic anhydrase