Final answer:
The entire contribution margin of units sold beyond the break-even point represents profit, which is 100% of the contribution margin. At this point, all fixed costs are covered, hence each additional unit's contribution margin directly adds to profits.
Step-by-step explanation:
The question is concerning the percentage of the contribution margin that is profit on units sold in excess of the break-even point. The contribution margin represents the portion of sales revenue that is not consumed by variable costs and therefore contributes to the coverage of fixed costs. Once the break-even point is reached, each additional unit sold contributes to profit, as fixed costs have already been covered. When a firm sells units beyond the break-even point, the contribution margin of those units essentially becomes the profit as fixed costs are no longer part of the consideration. Therefore, the correct answer to the question is (d) It's 100%, meaning that the entire contribution margin of units sold beyond the break-even point represents profit. This holds true as long as the selling price remains constant and the variable and fixed costs do not change.