Diffusion moves air molecules from an area of high pressure to an area of low pressure. Which of the following conditions would most likely cause air to move from outside of the body and into the lungs?
a. a low level of air pressure in the alveoli and a high level of air pressure in the lungs
b. a high level of air pressure in the alveoli and a low level of air pressure in the lungs
c. a low level of air pressure in the lungs and a high level of air pressure in the environment
d. a high level of air pressure in the lung and a low level of air pressure in the environment