Operational definitions are used for which of the following reasons? Answer A: They enable researchers to replicate studies by precisely describing the variables and how they are used.

Answer B: They exclude mental processes from being studied, as they are no longer considered part of the scientific study of psychology.

Answer C: They determine which test of statistical significance will be used to analyze the results of the experiment.

Answer D: They keep the participants in the control group from knowing they have received the placebo.

Answer E: They determine whether the experiment is better suited for a laboratory or a field setting.