With reference to a normal human being which one of the following statement is not correct ?

• A. Compared with skeletal muscles, the tissues of intestine are much more affected by the shortage of oxygen.
• B. In the arterial blood, haemoglobin is normally 97% saturated with oxygen.
• C. Pulmonary artery contains dexygenated blood.
• D. About 70% of the carbon dioxide entering the erythrocytes react with the water to form carbonic acid