In the tissues, high concentrations of carbon dioxide
(A) Increases the affinity of haemoglobin to both oxygen and hydrogen
(B) Increases the affinity of haemoglobin to oxygen but decreases its affinity to hydrogen
(C) Decreases the affinity of haemoglobin to oxygen but increases its affinity to hydrogen
(D) Decreases the affinity of haemoglobin to both oxygen and hydrogen