Which of the following is true regarding the contribution margin ratio of a company that produces only a single product? Select one: O a. The contribution margin ratio will decline as selling price declines. b. None of the given answer is correct. c. The contribution margin ratio divided by the selling price per unit equals the contribution margin per unit. d. The contribution margin ratio equals the sewing price per unit less the variable expense ratio. e. As fixed expenses decrease, the contribution margin ratio increases