Final answer:
An actively contracting muscle will cause the oxygen-hemoglobin saturation curve to shift, reflecting that hemoglobin releases a) more oxygen.
Step-by-step explanation:
An actively contracting muscle will cause local temperature to rise and produce acidic molecules.
The increase in temperature and decrease in pH result in the oxygen-hemoglobin saturation curve shifting to the right, indicating that hemoglobin releases more oxygen. This is because the high temperature and low pH reduce the affinity of hemoglobin for oxygen, causing the oxygen to dissociate from the hemoglobin more readily.
Therefore, more oxygen is released to the tissues when the muscle is actively contracting.