Your answer would be B. Hope this helped :)<span />
Answer:
The Cardiovascular System
Explanation:
The respiratory system draws air into the lungs. Oxygen diffuses through the walls of the alveoli and across the walls of the capillaries where it enteres the bloodstream. The oxygen molecules are picked up by red blood cells, which are pumped through the blood vessels by the action of the heart. As the red blood cells carrying oxygen pass through capillaries near the cells, oxygen diffuses into the cells.
The modern classification is based on a six Kingdom system-
<span>1- Animalia</span>
2- Plantae
3- Fungi
4- Protista
5- Archaea bacteria
6- <span>Eubacteria </span>
The answer is C the ancient photosynthetic prokayotes evolved into modern chloroplasts.
