The correct option is A The H+ released from carbonic acid combines with haemoglobin to form haemoglobinic acid
Haemoglobinic acid is a very weak acid formed inside the red blood cells when hydrogen ions produced by the dissociation of carbonic acid combine with the haemoglobin.
Oxyhaemoglobin of the erythrocyte is not alkaline 70 of CO2 is transferred as bicarbonate ion and is therefore acidic. About 20 - 25% of the carbon dioxide is transported in the blood in the form of carbamino haemoglobin. In lungs, the oxygen from the alveolus reaches the blood through simple diffusion.