Im not 100% sure but the best answer I can give is Prokaryotes because they came to be around the time oxygen did as well.
The answer is a. to determine what sort of data table will be most useful.
Controlled experiment is used parallel with experiment in which some alteration of the subject is induced. This is because this way can be compared in treated and non-treated subject. When sort of data table is necessary, using the controlled experiment, it can be determined what sort of data table will be most <span>useful.</span>
C. Dependent variable
The independent variable is what you want to change (ex amount of light given to plants)
The dependent variable is what changes because of the independent variable (ex the height of the plants)
So Independent is what you change, Dependent is what you measure