Which of the following conditions does NOT increase the number of red blood cells in the human body?
A. High altitude environment.
B. Low oxygen delivery to the tissues.
C. Increased erythropoietin production.
D. Increased carbon dioxide concentration in the blood.
Whereas decreased oxygen delivery to tissues (or a low blood oxygen concentration) will increase the number of red blood cells, increased carbon dioxide concentration will not. Changes in the number of red blood cells appear to be associated with changes in blood oxygen tension rather than in blood carbon dioxide tension.