Answer:
Option A, oxygen in the atmosphere
Explanation:
The highest level of oxygen reached during this phase of the geological cycle of earth. The oxygen level in Carboniferous period accounted for 35% as compared to 21% of oxygen in the atmosphere in present time.
Due to high oxygen content, the giant and wide varieties of terrestrial animal and plant species evolved. For example – size of insects and carwlies increased, plant became extremely giant, increase in number of tree ferns etc.
<span>Terrestrial radiation is energry that is emmited from the earth from the parts of solar radiation. Solar radiation is radiation and energy off the sun, however, only some of the radiation reches the eath's surface. I beleive the similarity is that both of the radiations originated from the sun.</span>
An independent variable is a variable which change is not affected by that of another variable. By process of elimination you can take out B and C. An independent variable can also change so that takes out A. That leaves D.
The third option, "other fungi growth".
