Answer: Hierarchical proportion
Explanation : hope this helps !
Bulgaria is the answer you're looking for.
Is there more to this question if not I can figure it out
The study is an experiment in light of the fact that the scientists control one variable to decide the impact on another.
An experiment is an investigation intended to contrast advantages of an intervention and standard medications, or no treatment, for example, another medication treatment or aversion program, or to indicate circumstances and end results. This sort of study is performed tentatively. Subjects are chosen from an examination populace, doled out to the different investigation gatherings, and observed after some time to decide the results that happen and are created by the new medication treatment, treatment, or intercession.
presenting is the root word or base word for this situation man