You didn't include a list, so omit anything that doesn't appear in your instructions. Here's structures in order of blood flow:
Superior and inferior vena cava
right atrium
tricuspid valve
right ventricle
pulmonary semilunar valve
pulmonary arteries (2 - one to each lung)
lungs
pulmonary veins (4 - two return from each lung)
left atrium
bicuspid, or mitral valve
left ventricle
aortic semilunar valve
ascending aorta
Among the given choices, the only positive effect that may be thought off with the increase in level of CO2 in the atmosphere is the increase of plant growth. Carbon dioxide is an essential compound in the photosynthesis of plants. Therefore, the answer should be letter C.
Evolution causes genetic material to adapt into variations that are beneficial for a species to survive
weathering will make it more difficult to read over time.