This is a easy question 28 hope this helps have a nice day.
Algae plants are considered to be one of the most important organisms on our planet because it produces a lot of the Earth's oxygen. All plants produce oxygen, but algae produces more than the usual green plant.
Your answer is: Produces most of the Earth's oxygen
Have an amazing day and stay hopeful!
The definitions of "sector 3" and "stratum D", the layout of the sectors,
and the behavior of the strata would go a long way toward explaining
that mysterious absence.