Given below are two statements about transport of O_2 and CO_2 ....

Statement (I) is correct. In the alveoli, the partial pressure of oxygen ($\text{pO}_2$) is high and the partial pressure of carbon dioxide ($\text{pCO}_2$) is low. Along with lesser $\text{H}^+$ concentration and lower temperature, these factors are highly favourable for the binding of oxygen with haemoglobin to form oxyhaemoglobin.

Statement (II) is correct. At the alveolar site where $\text{pCO}_2$ is low, the reaction catalyzed by the enzyme carbonic anhydrase proceeds in the reverse direction. Bicarbonate ions ($\text{HCO}_3^-$) and hydrogen ions ($\text{H}^+$) recombine to form carbonic acid, which then dissociates to release $\text{CO}_2$ and $\text{H}_2\text{O}$.

Therefore, both Statement (I) and Statement (II) are correct.

Answer: Both Statement (I) and Statement (II) are correct.