1. Air enters the nostrils.
2. Air passes from the trachea to the bronchi
3. Air diffuses from the alveoli to the blood cells.
4. Oxygen enters the blood cells.
5. Blood transports oxygen to other cells.
By polishing it, it becomes more clear which becomes so Clear that you could see your reflection.
I believe the answer is B: Earth's oceans absorb some of the carbon dioxide from the atmosphere.
Graphs that are clearly labeled are much less likely to be misread or misinterpreted.