Q: Which gas moves from the blood in the capillaries into the air?


Read this paragraph and choose the correct option from the provided answers:

Unlike oxygen, carbon dioxide is more concentrated in the blood in the capillaries surrounding the alveoli than it is in the air inside the alveoli. Therefore, carbon dioxide diffuses in the opposite direction. It moves out of the blood and into the air.

 Choices:

- nitrogen

- carbon monoxide

- oxygen

- carbon dioxide


A:
carbon dioxide