Final answer:
Venous blood has a lower hydrogen ion concentration than arterial blood.
Step-by-step explanation:
The correct statement is: d. Venous blood has a lower hydrogen ion concentration than arterial blood.
Arterial blood has a higher process_less strong hydrogen ion concentration than venous blood, which means it is more acidic. This is because arterial blood has just delivered oxygen and nutrients to tissues, and in the process, it picks up carbon dioxide, a waste product produced by cells. This carbon dioxide combines with water in the blood to form carbonic acid, leading to the higher hydrogen ion concentration in arterial blood.
Venous blood, on the other hand, has already picked up carbon dioxide from the tissues and is returning it to the lungs to be exhaled. This decreases the hydrogen ion concentration in venous blood, making it less acidic compared to arterial blood.