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