I belive the correct answer is D
Hope this helps :)
Answer:
The answer is natural selection
Explanation:
The modern theory of evolution was developed by Charles Darwin, an amateur English naturalist, in the 19th century
Electrons get “excited” or charged by sunlight, then they move on through the photosystem 2 and 1 along the etc or electron transport chain
Blood vessels visible in the posterior view of the heart include the Superior and inferior vena cava and the pulmonary veins. The superior vena cava and the inferior vena cava drain systemic venous blood into the posterior wall of the right atrium. The pulmonary veins transport blood from the lungs back to the heart and are best seen in posterior view of the heart. Other features visible in the posterior view include, right and left atrium, right and left ventricle, aorta, aortic arch, pulmonary veins and arteries, coronary sinus, coronary artery and posterior interventricular artery.
It is part of the cell theory