Physiology Transport of carbon monoxide (CO) is diffusion limited because A High affinity of CO for haemoglobin B Alveolar membrane is less permeable to CO C CO crosses epithelial barrier slowly D On exposure to air there is sudden increase in partial pressure 💡 Explanation Transport of carbon monoxide (CO) is diffusion limited because ✓ Correct Answer: A. High affinity of CO for haemoglobin