10 ineed the answer

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