Answer:
The correct answer is the control group or constants.
Step-by-step explanation:
The control group or the constants are the factors that remain the same in an experiment and also use as the factor to compare the other factors called variables that are subject to change in experiments.
The constant or the control group is the group that is not getting any treatment in or change in the experiments and uses as a standard to evaluates the other factors.
Thus, the correct answer is - the control group or constant.