A patient arrives at the emergency room after he became disoriented at home and passed out. After a bunch of tests, doctors determined that he has scar tissue from a previous lung infection; his current alveolar PO2 is 95 mmHg, his arterial PO2 is 75 mmHg, and his venous PCO2 is 40 mmHg. Choose which of the following you think is most likely to be the reason for his altered blood oxygen levels, and explain what evidence you are using to come to that conclusion. (2 marks)
a. improper amount of gases entering the alveolus
b. Improper diffusion across the membrane between the alveoli and the blood
c. Improper binding to hemoglobin