- A Raises hemoglobin's affinity for carbon monoxide instead
- B Lets hemoglobin bind oxygen more tightly in muscle capillaries
- C Lets hemoglobin release more oxygen at a given partial pressure
- D Stops further oxygen unloading at the tissue level
Correct answer: C. Lets hemoglobin release more oxygen at a given partial pressure
Explanation: A rightward-shifted curve (favoured by raised CO2, H+, and temperature during exercise) reflects lower hemoglobin-O2 affinity, so more oxygen is unloaded to meet the higher demand of active tissues.
Concept context
The mechanics of breathing, lung volumes, gas transport in blood, the Bohr effect, and respiratory regulation.