The correct option is A They carry about 20-25 per cent of CO2
Oxygen and carbon dioxide are circulated across the body through the blood in different forms. Nearly 70% of carbon dioxide is carried by the blood as bicarbonate, 20-25% as bound to RBCs, and around 7% in a dissolves state through plasma. However, in the case of oxygen, nearly 97% is transported by RBCs (as bound to haemoglobin), while the remaining 3% is carried in a dissolved state through the plasma.