Humans ferment lactic acid in muscles where oxygen becomes depleted, which is why sometimes if you finish a run and don't stretch soon you have have discomfort. <span />
The correct order that oxygen enters the body is definitely C.
Bronchi, then Lungs, bronchioles, alveoli, blood!
Good luck!!
An example of ATMOSPHERE affecting the BIOSPHERE. Atmosphere because it is AIR pollution and biosphere because it causes LUNG TISSUE damage.
The answer is B, because layers mix better at the poles.