Final answer:
Physiological changes that reduce hemoglobin's affinity for oxygen include a decrease in blood pH and an increase in body temperature, both associated with higher carbon dioxide levels.
Step-by-step explanation:
Hemoglobin is a protein in red blood cells responsible for transporting oxygen. Certain physiological changes can affect hemoglobin’s affinity for oxygen. The correct answer to which physiological changes reduce hemoglobin's affinity for oxygen is c. Decrease in blood pH and also an increase in body temperature. When carbon dioxide levels rise in the blood, more hydrogen ions are produced, leading to a lower pH. A reduced pH shifts the oxygen dissociation curve to the right, meaning hemoglobin has a lower affinity for oxygen which facilitates the release of oxygen to tissues where it is needed such as active skeletal muscle.