Answer the following question given this paragraph: 

In the lungs, oxygen diffuses out of the alveoli and into the capillaries surrounding the alveoli. Oxygen (about 98 percent) binds reversibly to the respiratory pigment hemoglobin found in red blood cells (RBCs). RBCs carry oxygen to the tissues where oxygen dissociates from the hemoglobin and diffuses into the cells of the tissues. More specifically, alveolar P O 2.


Q: In the lungs, oxygen diffuses out of the alveoli and into where?

 Choices:

- blood

- neurons

- cillia

- capillaries

A:
capillaries
