A simplified experiment showing the setup of a pith ball (a circular object) attached by a string to an insulated stand. The researcher tested how far away a charged glass rod can be held while still causing an attraction to the pith ball. Which statements accurately describe this experimental design? Select ALL that apply. A) An appropriate control could be a non-charged glass rod used for comparison. B) The dependent variable is the distance of the glass rod is from the pith ball. C) The independent variable is the distance of the glass rod is from the pith ball. D) The dependent variable is the level of attraction that the pith ball has to the charged rod. E) The independent variable is the level of attraction that the pith ball has to the charged rod.