Answer:
eveything that has organic material has cells, for example, rocks have molecules not cells
Explanation:
Answer:
The correct answer is B: conceptual hierarchy
The independent variable is that in which the result is dependent on. For experiments, this is usually the item being varied. For this case, what is being varied is that one group is given caffeine while the other is not. That makes the amount of caffeine given to be our independent variable.