Read the following two statements about the transport of oxygen in human blood and choose the option that correctly evaluates them.

• Statement I: About 97% of the oxygen carried in blood is bound to haemoglobin as oxyhaemoglobin, and each haemoglobin molecule can bind a maximum of four O₂ molecules.
• Statement II: A higher partial pressure of CO₂, a higher hydrogen ion concentration, and a higher temperature, as found in the tissues, all favour dissociation of oxygen from oxyhaemoglobin, helping O₂ unload where it is needed.